content: <PAGE>   1
      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE _____, 2001
  
                                                        Registration No. 333-
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                             --------------------------
  
  
                                      FORM S-8
                               REGISTRATION STATEMENT
  
                                        Under
                             The Securities Act of 1933
  
                             --------------------------
  
                               ALPHA INDUSTRIES, INC.
               (Exact Name of Registrant as Specified in Its Charter)
  
            DELAWARE                                         04-2302115
  (State or Other Jurisdiction of                         (I.R.S. Employer
  Incorporation or Organization)                       Identification Number)
  
             20 SYLVAN ROAD, WOBURN, MASSACHUSETTS 01801 (781) 935-5150
            (Address, Including Zip Code, and Telephone Number, Including
               Area Code, of Registrant's Principal Executive Offices)
  
  
                             --------------------------
  
  
                 ALPHA INDUSTRIES SAVINGS AND RETIREMENT 401(K) PLAN
  
                              (Full Title of the Plan)
  
  
                          JAMES K. JACOBS, GENERAL COUNSEL
                               ALPHA INDUSTRIES, INC.
                     20 SYLVAN ROAD, WOBURN, MASSACHUSETTS 01801
                                   (617) 824-4426
                        (Name, Address and Telephone Number,
                     Including Area Code, of Agent for Service)
  
                             --------------------------
  
  
                           CALCULATION OF REGISTRATION FEE
  <TABLE>
  <CAPTION>
  
  ==========================================================================================================
                                                            Proposed         Proposed
                                         Amount             Maximum           Maximum            Amount of
       Title of Each Class of            to Be           Offering Price      Aggregate         Registration
    Securities to Be Registered        Registered        Per Share (1)   Offering Price (1)      Fee (2)
  ----------------------------------------------------------------------------------------------------------
  <S>                               <C>                   <C>              <C>                 <C>
  Common Stock, $ .25 par  value    200,000 Shares (2)    $ 22.33          $ 4,466,000         $ 1,116.25
  ==========================================================================================================
  </TABLE>
  
  (1)  The registration fee has been calculated pursuant to Rule 457(c) under the
       Securities Act of 1933, as amended, on the basis of the average of the high
       and low reported price of the Common Stock of Alpha Industries, Inc. on the
       Nasdaq National Market on June 20, 2001.
  
  (2)  Such presently indeterminable number of additional shares of Common Stock
       are registered hereunder as may be issued in the event of a merger,
       consolidation, reorganization, recapitalization, stock dividend, stock
       split, stock combination or other similar change in the Common Stock.
  
  ================================================================================
  
  
  Page -1-
  <PAGE>   2
  
                                       PART II
  
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.
  
       The following documents are hereby incorporated by reference in this
  Registration Statement:
  
       (a)  The Registrant's Annual Report on Form 10-K for the fiscal year ended
            April 2, 2000 filed pursuant to Section 13(a) or 15(d) of the
            Securities Exchange Act of 1934, as amended (the "Exchange Act");
  
       (b)  The Registrant's Quarterly Reports on Form 10-Q for the fiscal
            quarters ended July 2, 2000, October 1, 2000 and December 31, 2000,
            filed pursuant to Section 13(a) or 15(d) of the Securities Exchange
            Act of 1934, as amended (the "Exchange Act");
  
       (c)  All other reports filed by the Registrant pursuant to Section 13(a) or
            15(d) of the Exchange Act since the end of the fiscal year covered by
            the Registrant's Annual Report referred to in (a) above; and
  
       (d)  The description of the Registrant's Capital Stock contained in the
            Registrant's Restated Certificate of Incorporation filed as Exhibit
            3(a) to the Registrant's Registration Statement on Form S-3
            (Registration No. 33-63857)), as amended by that Certificate of
            Amendment of Restated Certificate of Incorporation dated March 30,
            2000 filed as Exhibit 4(a) to this Registration Statement.
  
       All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14
  and 15(d) of the Exchange Act subsequent to the date hereof and prior to the
  filing of a post-effective amendment which indicates that all securities offered
  have been sold or which deregisters all securities then remaining unsold, shall
  be deemed to be incorporated by reference in this Registration Statement and to
  be a part hereof from the date of filing of such documents.
  
  ITEM 4. DESCRIPTION OF SECURITIES.
  
       Not Applicable.
  
  ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
       Not Applicable.
  
  
  Page -2-
  <PAGE>   3
  
  ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
       Article Tenth of the Registrant's Restated Certificate of Incorporation
  eliminates the personal liability of directors to the Registrant or its
  stockholders for monetary damages for breaches of their fiduciary duty (subject
  to certain exceptions, such as breaches of the duty of loyalty to registrant or
  its stockholders), and provides that the Registrant may indemnify its officers
  and directors to the full extent permitted by law.
  
       The Registrant's Amended and Restated By-laws include provisions for
  mandatory indemnification of its officers and directors provided certain
  conditions are met. Section 145 of the General Corporation Law of the State of
  Delaware authorizes a corporation to indemnify directors, officers, employees or
  agents of the corporation in non-derivative suits if such party acted in good
  faith and in a manner he or she reasonably believed to be in or not opposed to
  the best interests of the corporation and, with respect to any criminal action
  or proceeding, had no reasonable cause to believe his conduct was unlawful, as
  determined in accordance with the Delaware General Corporation Law. Section 145
  further provides that indemnification shall be provided if the party in question
  is successful on the merits or otherwise.
  
       The effect of these provisions would be to permit such indemnification by
  the Registrant for liabilities arising under the Securities Act of 1933, as
  amended, to the extent permitted under such act.
  
       The Registrant has directors' and officers' liability insurance.
  
  ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.
  
       Not Applicable.
  
  
  Page -3-
  <PAGE>   4
  
  ITEM 8.        EXHIBITS.
  
  Exhibit
  Number         Description
  --------       -----------
  
    4(a)         Certificate of Amendment of Restated Certificate of Incorporation
                 dated March 30, 2000
  
    4(b)         Specimen Certificate of Common Stock (filed as Exhibit 4(a) to
                 the Registrant's Registration Statement on Form S-3 (Registration
                 No. 33-63857)). *
  
    5            Legal Opinion of Testa Hurwitz & Thibeault, LLP
  
   23(a)         Consent of Testa Hurwitz & Thibeault, LLP (contained in
                 Exhibit 5)
  
   23(b)         Consent of KPMG LLP.
  
   24            Power of Attorney (included on the signature page of this
                 Registration Statement).
  
  ------------------
  *    Not filed herewith. In accordance with Rule 411 promulgated pursuant to the
       Securities Act of 1933, as amended, reference is made to documents
       previously filed with the Commission, which are incorporated by reference
       herein.
  
  The undersigned Registrant hereby undertakes that it will submit or has
  submitted the Alpha Industries Savings and Retirement 401(K) Plan and any
  amendment thereto to the Internal Revenue Service (IRS) in a timely manner and
  has made or will make all changes required by the IRS in order to qualify the
  Plan.
  
  ITEM 9.  UNDERTAKINGS.
  
       (a)  The undersigned Registrant hereby undertakes:
  
            (1)  To file, during any period in which offers or sales are being
  made, a post-effective amendment to this Registration Statement:
  
            (i)  To include any prospectus required by Section 10(a)(3) of the
  Securities Act;
  
            (ii) To reflect in the prospectus any facts or events arising after
  the effective date of the Registration Statement (or the most recent
  post-effective amendment thereof) which, individually or in the aggregate,
  represent a fundamental change in the information set forth in the Registration
  Statement;
  
  
  Page -4-
  <PAGE>   5
  
            (iii) To include any material information with respect to the plan of
  distribution not previously disclosed in the Registration Statement or any
  material change to such information in this Registration Statement;
  
            Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not
  apply if the information required to be included in a post-effective amendment
  by those paragraphs is contained in periodic reports filed with or furnished to
  the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the
  Securities Exchange Act that are incorporated by reference in the Registration
  Statement.
  
            (2)  That, for the purpose of determining liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein, and the
  offering of such securities at that time shall be deemed to be the initial bona
  fide offering thereof.
  
            (3)  To remove from registration by means of a post-effective
  amendment any of the securities being registered which remain unsold at the
  termination of the offering.
  
       (b)  The undersigned Registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
  Securities Exchange Act of 1934 that is incorporated by reference in the
  Registration Statement shall be deemed to be a new registration statement
  relating to the securities offered therein, and the offering of such securities
  at that time shall be deemed to be the initial bona fide offering thereof.
  
       (c)  Insofar as indemnification for liabilities arising under the
  Securities Act of 1933 may be permitted to directors, officers and controlling
  persons of the Registrant pursuant to the foregoing provisions, or otherwise,
  the Registrant has been advised that in the opinion of the Securities and
  Exchange Commission such indemnification is against public policy as expressed
  in the Act and is, therefore, unenforceable. In the event that a claim for
  indemnification against such liabilities (other than the payment by the
  registrant of expenses incurred or paid by a director, officer or controlling
  person of the registrant in the successful defense of any action, suit or
  proceeding) is asserted by such director, officer or controlling person in
  connection with the securities being registered, the registrant will, unless in
  the opinion of its counsel the matter has been settled by controlling precedent,
  submit to a court of appropriate jurisdiction the question whether such
  indemnification by it is against public policy as expressed in the Act and will
  be governed by the final adjudication of such issue.
  
  
                                 [SIGNATURES FOLLOW]
  
  
  Page -5-
  <PAGE>   6
  
                                     SIGNATURES
  
  THE REGISTRANT. Pursuant to the requirements of the Securities Act of 1933, the
  Registrant certifies that it has reasonable grounds to believe that it meets all
  of the requirements for filing on Form S-8 and has duly caused this Registration
  Statement to be signed on its behalf by the undersigned, thereunto duly
  authorized, in the City of Woburn, Commonwealth of Massachusetts, on June 25,
  2001.
  
                                          ALPHA INDUSTRIES, INC.
  
  
                                          By: /s/ David J. Aldrich
                                             -------------------------------
                                             DAVID J. ALDRICH
                                             PRESIDENT AND CHIEF EXECUTIVE OFFICER
  
  
  Page -6-
  <PAGE>   7
  
                                  POWER OF ATTORNEY
  
       KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
  below constitutes and appoints David J. Aldrich and Paul E. Vincent, and each of
  them (with full power to each of them to act alone), his true and lawful
  attorneys-in-fact and agents, with full power of substitution and
  resubstitution, for him and in his name, place and stead, in any and all
  capacities, to sign any or all amendments (including post-effective amendments)
  to this Registration Statement, and to file the same, with all exhibits thereto
  and other documents in connection therewith, with the Securities and Exchange
  Commission, granting unto said attorneys-in-fact and agents, and each of them,
  full power and authority to do and perform each and every act and thing
  requisite and necessary to be done in and about the premises, as fully to all
  intents and purposes as he might or could do in person, hereby ratifying and
  confirming all that said attorneys-in-fact and agents, or any of them, or their
  substitutes, may lawfully do or cause to be done by virtue hereof.
  
       Pursuant to the requirements of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  
  <TABLE>
  <CAPTION>
  
          SIGNATURE                       TITLE                            DATE
          ---------                       -----                            ----
  
  <S>                              <C>                                 <C>
      /s/ Thomas C. Leonard        Chairman of the Board               June 25, 2001
  ------------------------------
      THOMAS C. LEONARD
  
      /s/ David J. Aldrich         President, Chief Executive          June 25, 2001
  ------------------------------   Officer and Director
      DAVID J. ALDRICH
  
      /s/ Paul E. Vincent          Chief Financial Officer             June 25, 2001
  ------------------------------   Principal Financial Officer and
      PAUL E. VINCENT              Principal Accounting Officer
  
  
      /s/ George S. Kariotis       Director                            June 25, 2001
  ------------------------------
      GEORGE S. KARIOTIS
  
      /s/ Timothy R. Furey         Director                            June 25, 2001
  ------------------------------
      TIMOTHY R. FUREY
  
                                   Director                            June    , 2001
  ------------------------------
      JAMES W. HENDERSON
  
      /s/ David J. McLachlan       Director                            June 25, 2001
  ------------------------------
      DAVID J. MCLACHLAN
  
      /s/ Arthur Pappas            Director                            June 25, 2001
  ------------------------------
      ARTHUR PAPPAS
  
      /s/ Sidney Topol             Director                            June 25, 2001
  ------------------------------
      SIDNEY TOPOL
  
  </TABLE>
  
  
  Page -7-
  <PAGE>   8
  
                                    EXHIBIT INDEX
  
  Exhibit                                                               Sequential
  Number    Description                                                  Page No.
  -------   -----------
  
   4(a)     Certificate of Amendment of Restated Certificate of
            Incorporation dated March 30, 2000                               9
  
   4(b)     Specimen Certificate of Common Stock (filed as Exhibit 4(a)
            to the Registrant's Registration Statement on Form S-3
            (Registration No. 33-63857)). *
  
   5        Legal Opinion of Testa Hurwitz & Thibeault, LLP                 10
  
  23(a)     Consent of Testa Hurwitz & Thibeault, LLP (contained in
            Exhibit 5)
  
  23(b)     Consent of KPMG LLP.                                            11
  
  24        Power of Attorney (included on the signature page of this
            Registration Statement).
  
  ------------------
  *    Not filed herewith. In accordance with Rule 411 promulgated pursuant to the
       Securities Act of 1933, as amended, reference is made to the documents
       previously filed with the Commission, which are incorporated by reference
       herein.
  
  
  Page -8-
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metadata_filer: {"company-data": {"conformed-name": "ALPHA INDUSTRIES INC", "cik": "0000004127", "assigned-sic": "3674", "irs-number": "042302115", "state-of-incorporation": "DE", "fiscal-year-end": "0328"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-63818", "film-number": "1667124"}, "business-address": {"street1": "20 SYLVAN RD", "city": "WOBURN", "state": "MA", "zip": "01801", "phone": "6179355150"}, "mail-address": {"street1": "20 SYLVAN RD", "street2": "20 SYLVAN RD", "city": "WOBURN", "state": "MA", "zip": "01801"}}
text: 1
      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE _____, 2001
  
                                                        Registration No. 333-
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                             --------------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
  
                                        Under
                             The Securities Act of 1933
  
                             --------------------------
  
                               ALPHA INDUSTRIES, INC.
               (Exact Name of Registrant as Specified in Its Charter)
  
            DELAWARE                                         04-2302115
  (State or Other Jurisdiction of                         (I.R.S. Employer
  Incorporation or Organization)                       Identification Number)
  
             20 SYLVAN ROAD, WOBURN, MASSACHUSETTS 01801 (781) 935-5150
            (Address, Including Zip Code, and Telephone Number, Including
               Area Code, of Registrant's Principal Executive Offices)
  
                             --------------------------
  
                 ALPHA INDUSTRIES SAVINGS AND RETIREMENT 401(K) PLAN
  
                              (Full Title of the Plan)
  
                          JAMES K. JACOBS, GENERAL COUNSEL
                               ALPHA INDUSTRIES, INC.
                     20 SYLVAN ROAD, WOBURN, MASSACHUSETTS 01801
                                   (617) 824-4426
                        (Name, Address and Telephone Number,
                     Including Area Code, of Agent for Service)
  
                             --------------------------
  
                           CALCULATION OF REGISTRATION FEE
  ==========================================================================================================
                                                            Proposed         Proposed
                                         Amount             Maximum           Maximum            Amount of
       Title of Each Class of            to Be           Offering Price      Aggregate         Registration
    Securities to Be Registered        Registered        Per Share (1)   Offering Price (1)      Fee (2)
  ----------------------------------------------------------------------------------------------------------
  Common Stock, $ .25 par  value    200,000 Shares (2)    $ 22.33          $ 4,466,000         $ 1,116.25
  ==========================================================================================================
  (1)  The registration fee has been calculated pursuant to Rule 457(c) under the
       Securities Act of 1933, as amended, on the basis of the average of the high
       and low reported price of the Common Stock of Alpha Industries, Inc. on the
       Nasdaq National Market on June 20, 2001.
  
  (2)  Such presently indeterminable number of additional shares of Common Stock
       are registered hereunder as may be issued in the event of a merger,
       consolidation, reorganization, recapitalization, stock dividend, stock
       split, stock combination or other similar change in the Common Stock.
  
  ================================================================================
  
  Page -1-
  2
  
                                       PART II
  
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.
  
       The following documents are hereby incorporated by reference in this
  Registration Statement:
  
       (a)  The Registrant's Annual Report on Form 10-K for the fiscal year ended
            April 2, 2000 filed pursuant to Section 13(a) or 15(d) of the
            Securities Exchange Act of 1934, as amended (the "Exchange Act");
  
       (b)  The Registrant's Quarterly Reports on Form 10-Q for the fiscal
            quarters ended July 2, 2000, October 1, 2000 and December 31, 2000,
            filed pursuant to Section 13(a) or 15(d) of the Securities Exchange
            Act of 1934, as amended (the "Exchange Act");
  
       (c)  All other reports filed by the Registrant pursuant to Section 13(a) or
            15(d) of the Exchange Act since the end of the fiscal year covered by
            the Registrant's Annual Report referred to in (a) above; and
  
       (d)  The description of the Registrant's Capital Stock contained in the
            Registrant's Restated Certificate of Incorporation filed as Exhibit
            3(a) to the Registrant's Registration Statement on Form S-3
            (Registration No. 33-63857)), as amended by that Certificate of
            Amendment of Restated Certificate of Incorporation dated March 30,
            2000 filed as Exhibit 4(a) to this Registration Statement.
  
       All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14
  and 15(d) of the Exchange Act subsequent to the date hereof and prior to the
  filing of a post-effective amendment which indicates that all securities offered
  have been sold or which deregisters all securities then remaining unsold, shall
  be deemed to be incorporated by reference in this Registration Statement and to
  be a part hereof from the date of filing of such documents.
  
  ITEM 4. DESCRIPTION OF SECURITIES.
  
       Not Applicable.
  
  ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
       Not Applicable.
  
  Page -2-
  3
  
  ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
       Article Tenth of the Registrant's Restated Certificate of Incorporation
  eliminates the personal liability of directors to the Registrant or its
  stockholders for monetary damages for breaches of their fiduciary duty (subject
  to certain exceptions, such as breaches of the duty of loyalty to registrant or
  its stockholders), and provides that the Registrant may indemnify its officers
  and directors to the full extent permitted by law.
  
       The Registrant's Amended and Restated By-laws include provisions for
  mandatory indemnification of its officers and directors provided certain
  conditions are met. Section 145 of the General Corporation Law of the State of
  Delaware authorizes a corporation to indemnify directors, officers, employees or
  agents of the corporation in non-derivative suits if such party acted in good
  faith and in a manner he or she reasonably believed to be in or not opposed to
  the best interests of the corporation and, with respect to any criminal action
  or proceeding, had no reasonable cause to believe his conduct was unlawful, as
  determined in accordance with the Delaware General Corporation Law. Section 145
  further provides that indemnification shall be provided if the party in question
  is successful on the merits or otherwise.
  
       The effect of these provisions would be to permit such indemnification by
  the Registrant for liabilities arising under the Securities Act of 1933, as
  amended, to the extent permitted under such act.
  
       The Registrant has directors' and officers' liability insurance.
  
  ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.
  
       Not Applicable.
  
  Page -3-
  4
  
  ITEM 8.        EXHIBITS.
  
  Exhibit
  Number         Description
  --------       -----------
  
    4(a)         Certificate of Amendment of Restated Certificate of Incorporation
                 dated March 30, 2000
  
    4(b)         Specimen Certificate of Common Stock (filed as Exhibit 4(a) to
                 the Registrant's Registration Statement on Form S-3 (Registration
                 No. 33-63857)). *
  
    5            Legal Opinion of Testa Hurwitz & Thibeault, LLP
  
   23(a)         Consent of Testa Hurwitz & Thibeault, LLP (contained in
                 Exhibit 5)
  
   23(b)         Consent of KPMG LLP.
  
   24            Power of Attorney (included on the signature page of this
                 Registration Statement).
  
  ------------------
  *    Not filed herewith. In accordance with Rule 411 promulgated pursuant to the
       Securities Act of 1933, as amended, reference is made to documents
       previously filed with the Commission, which are incorporated by reference
       herein.
  
  The undersigned Registrant hereby undertakes that it will submit or has
  submitted the Alpha Industries Savings and Retirement 401(K) Plan and any
  amendment thereto to the Internal Revenue Service (IRS) in a timely manner and
  has made or will make all changes required by the IRS in order to qualify the
  Plan.
  
  ITEM 9.  UNDERTAKINGS.
  
       (a)  The undersigned Registrant hereby undertakes:
  
            (1)  To file, during any period in which offers or sales are being
  made, a post-effective amendment to this Registration Statement:
  
            (i)  To include any prospectus required by Section 10(a)(3) of the
  Securities Act;
  
            (ii) To reflect in the prospectus any facts or events arising after
  the effective date of the Registration Statement (or the most recent
  post-effective amendment thereof) which, individually or in the aggregate,
  represent a fundamental change in the information set forth in the Registration
  Statement;
  
  Page -4-
  5
  
            (iii) To include any material information with respect to the plan of
  distribution not previously disclosed in the Registration Statement or any
  material change to such information in this Registration Statement;
  
            Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not
  apply if the information required to be included in a post-effective amendment
  by those paragraphs is contained in periodic reports filed with or furnished to
  the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the
  Securities Exchange Act that are incorporated by reference in the Registration
  Statement.
  
            (2)  That, for the purpose of determining liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein, and the
  offering of such securities at that time shall be deemed to be the initial bona
  fide offering thereof.
  
            (3)  To remove from registration by means of a post-effective
  amendment any of the securities being registered which remain unsold at the
  termination of the offering.
  
       (b)  The undersigned Registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
  Securities Exchange Act of 1934 that is incorporated by reference in the
  Registration Statement shall be deemed to be a new registration statement
  relating to the securities offered therein, and the offering of such securities
  at that time shall be deemed to be the initial bona fide offering thereof.
  
       (c)  Insofar as indemnification for liabilities arising under the
  Securities Act of 1933 may be permitted to directors, officers and controlling
  persons of the Registrant pursuant to the foregoing provisions, or otherwise,
  the Registrant has been advised that in the opinion of the Securities and
  Exchange Commission such indemnification is against public policy as expressed
  in the Act and is, therefore, unenforceable. In the event that a claim for
  indemnification against such liabilities (other than the payment by the
  registrant of expenses incurred or paid by a director, officer or controlling
  person of the registrant in the successful defense of any action, suit or
  proceeding) is asserted by such director, officer or controlling person in
  connection with the securities being registered, the registrant will, unless in
  the opinion of its counsel the matter has been settled by controlling precedent,
  submit to a court of appropriate jurisdiction the question whether such
  indemnification by it is against public policy as expressed in the Act and will
  be governed by the final adjudication of such issue.
  
                                 [SIGNATURES FOLLOW]
  
  Page -5-
  6
  
                                     SIGNATURES
  
  THE REGISTRANT. Pursuant to the requirements of the Securities Act of 1933, the
  Registrant certifies that it has reasonable grounds to believe that it meets all
  of the requirements for filing on Form S-8 and has duly caused this Registration
  Statement to be signed on its behalf by the undersigned, thereunto duly
  authorized, in the City of Woburn, Commonwealth of Massachusetts, on June 25,
  2001.
  
                                          ALPHA INDUSTRIES, INC.
  
                                          By: /s/ David J. Aldrich
                                             -------------------------------
                                             DAVID J. ALDRICH
                                             PRESIDENT AND CHIEF EXECUTIVE OFFICER
  
  Page -6-
  7
  
                                  POWER OF ATTORNEY
  
       KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
  below constitutes and appoints David J. Aldrich and Paul E. Vincent, and each of
  them (with full power to each of them to act alone), his true and lawful
  attorneys-in-fact and agents, with full power of substitution and
  resubstitution, for him and in his name, place and stead, in any and all
  capacities, to sign any or all amendments (including post-effective amendments)
  to this Registration Statement, and to file the same, with all exhibits thereto
  and other documents in connection therewith, with the Securities and Exchange
  Commission, granting unto said attorneys-in-fact and agents, and each of them,
  full power and authority to do and perform each and every act and thing
  requisite and necessary to be done in and about the premises, as fully to all
  intents and purposes as he might or could do in person, hereby ratifying and
  confirming all that said attorneys-in-fact and agents, or any of them, or their
  substitutes, may lawfully do or cause to be done by virtue hereof.
  
       Pursuant to the requirements of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  SIGNATURE                       TITLE                            DATE
          ---------                       -----                            ----
  /s/ Thomas C. Leonard        Chairman of the Board               June 25, 2001
  ------------------------------
      THOMAS C. LEONARD
  
      /s/ David J. Aldrich         President, Chief Executive          June 25, 2001
  ------------------------------   Officer and Director
      DAVID J. ALDRICH
  
      /s/ Paul E. Vincent          Chief Financial Officer             June 25, 2001
  ------------------------------   Principal Financial Officer and
      PAUL E. VINCENT              Principal Accounting Officer
  
      /s/ George S. Kariotis       Director                            June 25, 2001
  ------------------------------
      GEORGE S. KARIOTIS
  
      /s/ Timothy R. Furey         Director                            June 25, 2001
  ------------------------------
      TIMOTHY R. FUREY
  
                                   Director                            June    , 2001
  ------------------------------
      JAMES W. HENDERSON
  
      /s/ David J. McLachlan       Director                            June 25, 2001
  ------------------------------
      DAVID J. MCLACHLAN
  
      /s/ Arthur Pappas            Director                            June 25, 2001
  ------------------------------
      ARTHUR PAPPAS
  
      /s/ Sidney Topol             Director                            June 25, 2001
  ------------------------------
      SIDNEY TOPOL
  Page -7-
  8
  
                                    EXHIBIT INDEX
  
  Exhibit                                                               Sequential
  Number    Description                                                  Page No.
  -------   -----------
  
   4(a)     Certificate of Amendment of Restated Certificate of
            Incorporation dated March 30, 2000                               9
  
   4(b)     Specimen Certificate of Common Stock (filed as Exhibit 4(a)
            to the Registrant's Registration Statement on Form S-3
            (Registration No. 33-63857)). *
  
   5        Legal Opinion of Testa Hurwitz & Thibeault, LLP                 10
  
  23(a)     Consent of Testa Hurwitz & Thibeault, LLP (contained in
            Exhibit 5)
  
  23(b)     Consent of KPMG LLP.                                            11
  
  24        Power of Attorney (included on the signature page of this
            Registration Statement).
  
  ------------------
  *    Not filed herewith. In accordance with Rule 411 promulgated pursuant to the
       Securities Act of 1933, as amended, reference is made to the documents
       previously filed with the Commission, which are incorporated by reference
       herein.
  
  Page -8-