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

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    <periodOfReport>2006-11-10</periodOfReport>

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    <issuer>
        <issuerCik>0000097745</issuerCik>
        <issuerName>THERMO FISHER SCIENTIFIC INC.</issuerName>
        <issuerTradingSymbol>TMO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001033876</rptOwnerCik>
            <rptOwnerName>MEISTER PAUL M</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>
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            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-11-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
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            <transactionAmounts>
                <transactionShares>
                    <value>99279</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>575400.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
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        <nonDerivativeTransaction>
            <securityTitle>
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            </securityTitle>
            <transactionDate>
                <value>2006-11-16</value>
            </transactionDate>
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                <transactionFormType>4</transactionFormType>
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                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionShares>
                    <value>225400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>43.79</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>350000.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-11-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionShares>
                    <value>424600</value>
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                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>774600.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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                    <value></value>
                </natureOfOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
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                </transactionShares>
                <transactionPricePerShare>
                    <value>43.87</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
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                <sharesOwnedFollowingTransaction>
                    <value>350000.00</value>
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                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-11-20</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
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            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>450000.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
                <value>2006-11-20</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
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            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>43.71</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>350000.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-11-10</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>154425</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>45.03</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>829787.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trusts</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-11-20</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-11-09</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-01-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>100000.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>240725.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-11-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>99279</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-11-09</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-01-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>99279.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>765325.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-11-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>424600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-11-09</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-01-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>424600.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>340725.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The exercise and sale of the option shares were accomplished pursuant to a 10b5-1(c) sales plan adopted on November 13, 2006.</footnote>
        <footnote id="F2">The sales price shown is the average sales price for directly held shares and all option shares sold on November 16, 2006, actual denominations are as follows:4,200 shares at $43.70; 5,500 shares at $43.71; 10,200 shares at $43.72; 29,900 shares at $43.73; 13,000 shares at $43.74; 77,700 shares at $43.75; 1,700 shares at $43.76; 5,000 shares at $43.77; 5,100 shares at $43.78;  1,050 shares at $43.82; 1,650 shares at $43.83; 15,000 shares at $43.84; 11,400 shares at $43.85; 400 shares at $43.86; 8,500 shares at $43.90; 3,500 shares at $43.91; 23,200 shares at $43.95; 8,400 shares at $43.98.</footnote>
        <footnote id="F3">The sales price shown is the average sales price for all option shares sold on November 17, 2006, actual denominations are as follows:13,600 shares at $43.55; 1,000 shares at $43.56; 1,800 shares at $43.57; 1,100 shares at $43.58; 600 shares at $43.59; 27,500 shares at $43.60; 1,600 shares at $43.61; 300 shares at $43.63; 800 shares at $43.64;  27,100 shares at $43.65; 7,400 shares at $43.66; 2,500 shares at $43.67; 28,200 shares at $43.68; 18,700 shares at $43.69; 20,200 shares at $43.70; 2,100 shares at $43.71; 3,400 shares at $43.72; 5,700 shares at $43.73;
6,400 shares at $43.74; 5,000 shares at $43.75; 25,000 shares at $43.80; 100 shares at $43.85; 1,300 shares at $43.86; 500 shares at $43.87; 2,100 shares at $43.88; 5,600 shares at $43.89; 15,400 shares at $43.90;  67,300 shares at $44.00; 23,500 shares at $44.05; 12,500 shares at $44.06; 3,300 shares at $44.08; 24,500 shares at $44.09; 66,400 shares at $44.10; 2,100 shares at $44.15.</footnote>
        <footnote id="F4">The sales price shown is the average sales price for all option shares sold on November 20, 2006, actual denominations are as follows: 6,600 shares at $43.50; 400 shares at $43.52; 100 shares at $43.58; 1,100 shares at $43.59; 6,900 shares at $43.60; 300 shares at $43.61;  1,600 shares at $43.62; 20,000 shares at $43.67; 10,000 shares at $43.70;  300 shares at $43.71; 2,700 shares at $43.72; 25,000 shares at $43.75; 25,000 shares at $43.80.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Barbara J. Lucas, Attorney-in-Fact for Paul M. Meister</signatureName>
        <signatureDate>2006-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2006-11-10
0
0000097745
THERMO FISHER SCIENTIFIC INC.
TMO
0001033876
MEISTER PAUL M
81 WYMAN STREET
P.O. BOX 9046
WALTHAM
MA
024549046
1
0
0
0
Common Stock
2006-11-16
4
M
0
99279
4.75
A
575400.00
D
Common Stock
2006-11-16
4
S
0
225400
43.79
D
350000.00
D
Common Stock
2006-11-17
4
M
0
424600
4.75
A
774600.00
D
Common Stock
2006-11-17
4
S
0
424600
43.87
D
350000.00
D
Common Stock
2006-11-20
4
M
0
100000
4.75
A
450000.00
D
Common Stock
2006-11-20
4
S
0
100000
43.71
D
350000.00
D
Common Stock
2006-11-10
4
F
0
154425
45.03
D
829787.00
I
By Trusts
Stock Option (Right to Buy)
4.75
2006-11-20
4
M
0
100000
0
D
2006-11-09
2008-01-21
Common Stock
100000.00
240725.00
D
Stock Option (Right to Buy)
4.75
2006-11-16
4
M
0
99279
0
D
2006-11-09
2008-01-21
Common Stock
99279.00
765325.00
D
Stock Option (Right to Buy)
4.75
2006-11-17
4
M
0
424600
0
D
2006-11-09
2008-01-21
Common Stock
424600.00
340725.00
D
The exercise and sale of the option shares were accomplished pursuant to a 10b5-1(c) sales plan adopted on November 13, 2006.
The sales price shown is the average sales price for directly held shares and all option shares sold on November 16, 2006, actual denominations are as follows:4,200 shares at $43.70; 5,500 shares at $43.71; 10,200 shares at $43.72; 29,900 shares at $43.73; 13,000 shares at $43.74; 77,700 shares at $43.75; 1,700 shares at $43.76; 5,000 shares at $43.77; 5,100 shares at $43.78;  1,050 shares at $43.82; 1,650 shares at $43.83; 15,000 shares at $43.84; 11,400 shares at $43.85; 400 shares at $43.86; 8,500 shares at $43.90; 3,500 shares at $43.91; 23,200 shares at $43.95; 8,400 shares at $43.98.
The sales price shown is the average sales price for all option shares sold on November 17, 2006, actual denominations are as follows:13,600 shares at $43.55; 1,000 shares at $43.56; 1,800 shares at $43.57; 1,100 shares at $43.58; 600 shares at $43.59; 27,500 shares at $43.60; 1,600 shares at $43.61; 300 shares at $43.63; 800 shares at $43.64;  27,100 shares at $43.65; 7,400 shares at $43.66; 2,500 shares at $43.67; 28,200 shares at $43.68; 18,700 shares at $43.69; 20,200 shares at $43.70; 2,100 shares at $43.71; 3,400 shares at $43.72; 5,700 shares at $43.73;
6,400 shares at $43.74; 5,000 shares at $43.75; 25,000 shares at $43.80; 100 shares at $43.85; 1,300 shares at $43.86; 500 shares at $43.87; 2,100 shares at $43.88; 5,600 shares at $43.89; 15,400 shares at $43.90;  67,300 shares at $44.00; 23,500 shares at $44.05; 12,500 shares at $44.06; 3,300 shares at $44.08; 24,500 shares at $44.09; 66,400 shares at $44.10; 2,100 shares at $44.15.
The sales price shown is the average sales price for all option shares sold on November 20, 2006, actual denominations are as follows: 6,600 shares at $43.50; 400 shares at $43.52; 100 shares at $43.58; 1,100 shares at $43.59; 6,900 shares at $43.60; 300 shares at $43.61;  1,600 shares at $43.62; 20,000 shares at $43.67; 10,000 shares at $43.70;  300 shares at $43.71; 2,700 shares at $43.72; 25,000 shares at $43.75; 25,000 shares at $43.80.
By: Barbara J. Lucas, Attorney-in-Fact for Paul M. Meister
2006-11-20