<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-07-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000097745</issuerCik>
        <issuerName>THERMO ELECTRON CORP</issuerName>
        <issuerTradingSymbol>TMO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001190290</rptOwnerCik>
            <rptOwnerName>ULLIAN ELAINE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>81 WYMAN STREET</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 9046</rptOwnerStreet2>
            <rptOwnerCity>WALTHAM</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>024549046</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-07-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>638.89</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>638.89</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12944.96</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Convertible into Common Stock on a 1-for-1 basis.</footnote>
        <footnote id="F2">Represents stock units credited to the Reporting Person's account as of July 1, 2006, at a price of $36.00 per unit pursuant to the Issuer's Deferred Compensation Plan for Directors (the 'Plan').  Director's fees and retainers are deferred quarterly under the Plan as Common Stock units based on (a) the average closing price of the stock for the 5 days prior to the end of the quarter with respect to fees and retainers deferred on or prior to December 31, 2004, and (b) the average of the opening and closing price of the stock as of the quarter end with respect to fees and retainers deferred after December 31, 2004.  The shares are distributable as stock upon cessation of director service (for any reason), a change of control or, with respect to stock units credited for fees and retainers deferred on or prior to December 31, 2004 only, retirement from principal occupation.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>By: Barbara J. Lucas, Attorney-in-Fact for Elaine S. Ullian</signatureName>
        <signatureDate>2006-07-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
[{"type": "4", "sequence": "1", "filename": "ull328.xml", "secsgml_size_bytes": 4748}]
X0202
4
2006-07-01
0
0000097745
THERMO ELECTRON CORP
TMO
0001190290
ULLIAN ELAINE
81 WYMAN STREET
P.O. BOX 9046
WALTHAM
MA
024549046
1
0
0
0
Phantom Stock Units
2006-07-01
4
A
0
638.89
A
Common Stock
638.89
12944.96
D
Convertible into Common Stock on a 1-for-1 basis.
Represents stock units credited to the Reporting Person's account as of July 1, 2006, at a price of $36.00 per unit pursuant to the Issuer's Deferred Compensation Plan for Directors (the 'Plan').  Director's fees and retainers are deferred quarterly under the Plan as Common Stock units based on (a) the average closing price of the stock for the 5 days prior to the end of the quarter with respect to fees and retainers deferred on or prior to December 31, 2004, and (b) the average of the opening and closing price of the stock as of the quarter end with respect to fees and retainers deferred after December 31, 2004.  The shares are distributable as stock upon cessation of director service (for any reason), a change of control or, with respect to stock units credited for fees and retainers deferred on or prior to December 31, 2004 only, retirement from principal occupation.
By: Barbara J. Lucas, Attorney-in-Fact for Elaine S. Ullian
2006-07-05