<SEC-DOCUMENT>0001715912-25-000004.txt : 20251218
<SEC-HEADER>0001715912-25-000004.hdr.sgml : 20251218
<ACCEPTANCE-DATETIME>20251218170505
ACCESSION NUMBER:		0001715912-25-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251216
FILED AS OF DATE:		20251218
DATE AS OF CHANGE:		20251218

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Evans Eileen
		CENTRAL INDEX KEY:			0001715912
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30941
		FILM NUMBER:		251583869

	MAIL ADDRESS:	
		STREET 1:		C/O AXCELIS TECHNOLOGIES
		STREET 2:		108 CHERRY HILL DRIVE
		CITY:			BEVERLY
		STATE:			MA
		ZIP:			01915

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>form4-12182025_051201.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-12-16</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001715912</rptOwnerCik>
            <rptOwnerName>Evans Eileen</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>108 CHERRY HILL DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BEVERLY</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01915</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>EVP, General Counsel and Sec'y</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1378</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>86.32</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24406</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This forfeiture of shares for tax withholding purposes relates to the vesting on December 16, 2025 of 2,850 service vesting restricted stock units granted to the executive in December 2024. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested restricted stock units.</footnote>
        <footnote id="F2">Represents the closing price of the common stock on the date of the tax withholding.</footnote>
        <footnote id="F3">Of the shares held after this vesting event on December 16, 2025, 22,934 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</signatureName>
        <signatureDate>2025-12-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
