<SEC-DOCUMENT>0001338515-26-000004.txt : 20260604
<SEC-HEADER>0001338515-26-000004.hdr.sgml : 20260604
<ACCEPTANCE-DATETIME>20260604170507
ACCESSION NUMBER:		0001338515-26-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260603
FILED AS OF DATE:		20260604
DATE AS OF CHANGE:		20260604

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Sayiner Necip
		CENTRAL INDEX KEY:			0001338515
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30941
		FILM NUMBER:		261065893

	MAIL ADDRESS:	
		STREET 1:		C/O RAMBUS INC
		STREET 2:		4453 NORTH FIRST STREET, SUITE 100
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AXCELIS TECHNOLOGIES INC
		CENTRAL INDEX KEY:			0001113232
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		ORGANIZATION NAME:           	06 Technology
		EIN:				341818596
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		108 CHERRY HILL DRIVE
		CITY:			BEVERLY
		STATE:			MA
		ZIP:			01915
		BUSINESS PHONE:		978-787-4000

	MAIL ADDRESS:	
		STREET 1:		108 CHERRY HILL DRIVE
		CITY:			BEVERLY
		STATE:			MA
		ZIP:			01915

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EATON SEMICONDUCTOR EQUIPMENT INC
		DATE OF NAME CHANGE:	20000501
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4-06042026_050601.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-06-03</periodOfReport>

    <issuer>
        <issuerCik>0001113232</issuerCik>
        <issuerName>AXCELIS TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>ACLS</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001338515</rptOwnerCik>
            <rptOwnerName>Sayiner Necip</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O AXCELIS TECHNOLOGIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>108 CHERRY HILL DRIVE</rptOwnerStreet2>
            <rptOwnerCity>BEVERLY</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01915</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-06-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1586</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>157.4422</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7112</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $157.4100 to $157.7100, inclusive. The reporting person undertakes to provide to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F2">Of the shares held after this sale on June 3, 2026, 2,110 shares were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Eileen J. Evans, Attorney-in-Fact</signatureName>
        <signatureDate>2026-06-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
