<SEC-DOCUMENT>0001226867-17-000002.txt : 20170526
<SEC-HEADER>0001226867-17-000002.hdr.sgml : 20170526
<ACCEPTANCE-DATETIME>20170526145459
ACCESSION NUMBER:		0001226867-17-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170524
FILED AS OF DATE:		20170526
DATE AS OF CHANGE:		20170526

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			OLSON PAUL L H
		CENTRAL INDEX KEY:			0001226867

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32598
		FILM NUMBER:		17873565

	MAIL ADDRESS:	
		STREET 1:		C/O ENTEGRIS INC
		STREET 2:		3500 LYMAN BLVD
		CITY:			CHASKA
		STATE:			MN
		ZIP:			55318
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-05-24</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001226867</rptOwnerCik>
            <rptOwnerName>OLSON PAUL L H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>855 VILLAGE CENTER DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>PMB 378</rptOwnerStreet2>
            <rptOwnerCity>NORTH OAKS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55127</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-05-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>55481</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-05-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5133</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60614</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These Restricted Stock Units vest in full on the earlier of (1) the anniversary of the date of the grant, or (2) the date of the Company's 2018 Annual Meeting of Stockholders.</footnote>
        <footnote id="F2">These shares were awarded on May 24, 2017 as Restricted Stock Units, payable solely in Common Stock, pursuant to the Entegris, Inc. 2010 Stock Plan which provides for the award of Restricted Stock Units to independent directors in consideration for services as such.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Sue Lee, Attorney-In-Fact for Paul L.H. Olson</signatureName>
        <signatureDate>2017-05-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
