<SEC-DOCUMENT>0001607961-18-000002.txt : 20180214
<SEC-HEADER>0001607961-18-000002.hdr.sgml : 20180214
<ACCEPTANCE-DATETIME>20180214173845
ACCESSION NUMBER:		0001607961-18-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180212
FILED AS OF DATE:		20180214
DATE AS OF CHANGE:		20180214

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Marshall Gregory Bryan
		CENTRAL INDEX KEY:			0001607961

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32598
		FILM NUMBER:		18614179

	MAIL ADDRESS:	
		STREET 1:		62 CHESTNUT ROAD
		CITY:			TYNGSBOROUGH
		STATE:			MA
		ZIP:			01879

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ENTEGRIS INC
		CENTRAL INDEX KEY:			0001101302
		STANDARD INDUSTRIAL CLASSIFICATION:	PLASTICS PRODUCTS, NEC [3089]
		IRS NUMBER:				411941551
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		129 CONCORD ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821
		BUSINESS PHONE:		9784366500

	MAIL ADDRESS:	
		STREET 1:		129 CONCORD ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
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    <periodOfReport>2018-02-12</periodOfReport>

    <issuer>
        <issuerCik>0001101302</issuerCik>
        <issuerName>ENTEGRIS INC</issuerName>
        <issuerTradingSymbol>ENTG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001607961</rptOwnerCik>
            <rptOwnerName>Marshall Gregory Bryan</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>62 CHESTNUT ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TYNGSBORO</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01879</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Qual, EHS &amp; EBS</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
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            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-02-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionShares>
                    <value>2980</value>
                    <footnoteId id="F1"/>
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                <transactionPricePerShare>
                    <value>0</value>
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                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
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                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.10</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-02-12</value>
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                </transactionShares>
                <transactionPricePerShare>
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                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-02-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9484</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>9484</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These shares are restricted stock units with restrictions that lapse over a four year period with respect to 25% of these shares per year, starting February 19, 2019 and thereafter on February 19, 2020, February 19, 2021 and February 19, 2022.</footnote>
        <footnote id="F2">Awarded pursuant to the Entegris, Inc. 2010 Stock Plan, as amended, in consideration of services as an employee.</footnote>
        <footnote id="F3">These shares include 415.889 shares acquired under the Entegris, Inc. Employee Stock Purchase Plan on December 29, 2017.</footnote>
        <footnote id="F4">Awarded in connection with the settlement of performance share units for the 2015-2017 performance cycle.</footnote>
        <footnote id="F5">Shares automatically withheld upon settlement of performance share units to satisfy tax withholding obligations.</footnote>
        <footnote id="F6">The option vests in four equal annual installments starting on February 19, 2019 and thereafter on February 19, 2020, February 19, 2021 and February 19, 2022.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Sue Lee, Attorney-In-Fact for Gregory Marshall</signatureName>
        <signatureDate>2018-02-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
