-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 OdlmkqnlWtuZERzKAu68DgnilJc0P0SgCOw4zBfk68TB06O1T9XR6/OzTk6zb3Ej
 dpgNqAtxm5LBOxhZWg+ZeQ==

<SEC-DOCUMENT>0001275843-09-000063.txt : 20091127
<SEC-HEADER>0001275843-09-000063.hdr.sgml : 20091126
<ACCEPTANCE-DATETIME>20091127104813
ACCESSION NUMBER:		0001275843-09-000063
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091125
FILED AS OF DATE:		20091127
DATE AS OF CHANGE:		20091127

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WERNER RAE ANN
		CENTRAL INDEX KEY:			0001229062

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21321
		FILM NUMBER:		091209620

	MAIL ADDRESS:	
		STREET 1:		17075 THORNMINT COURT
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92127

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CYMER INC
		CENTRAL INDEX KEY:			0000897067
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				330175463
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		17075 THORNMINT COURT
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92127
		BUSINESS PHONE:		8583857300

	MAIL ADDRESS:	
		STREET 1:		17075 THORNMINT COURT
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92127-1815

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CYMER LASER TECHNOLOGIES
		DATE OF NAME CHANGE:	19960608
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-11-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000897067</issuerCik>
        <issuerName>CYMER INC</issuerName>
        <issuerTradingSymbol>CYMI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001229062</rptOwnerCik>
            <rptOwnerName>WERNER RAE ANN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>17075 THORNMINT COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92127</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP Corporate Controller &amp; CAO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-11-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3326</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.9</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3326</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-11-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3326</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>34.29</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.9</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-11-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3326</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>34.29</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-07-01</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-07-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3326</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Sale price ranged from $34.28 to $34.33</footnote>
        <footnote id="F2">The option vests 25% one year after the vesting commencement date and 1/48 of the shares subject to the option each month thereafter.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Cathy Wingenbach, Attorney-in-Fact  For: Rae Ann Werner</signatureName>
        <signatureDate>2009-11-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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