<SEC-DOCUMENT>0001415889-25-006547.txt : 20250304
<SEC-HEADER>0001415889-25-006547.hdr.sgml : 20250304
<ACCEPTANCE-DATETIME>20250304163025
ACCESSION NUMBER:		0001415889-25-006547
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250228
FILED AS OF DATE:		20250304
DATE AS OF CHANGE:		20250304

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Redinbo Greg
		CENTRAL INDEX KEY:			0001940017
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30941
		FILM NUMBER:		25705135

	MAIL ADDRESS:	
		STREET 1:		AXCELIS TECHNOLOGIES, INC.
		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
		IRS NUMBER:				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>form4-03042025_040321.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-02-28</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001940017</rptOwnerCik>
            <rptOwnerName>Redinbo Greg</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <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>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>EVP MARKETING AND APPLICATIONS</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-02-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>471</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>54.79</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22632</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-02-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>749</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>54.79</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21883</value>
                    <footnoteId id="F5"/>
                </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 February 28, 2025 of performance based restricted stock units (&quot;2023 PRSUs&quot;) granted to the executive in   May 2023.  The units vesting on the 2023 PRSUs were deemed earned by the Compensation Committee in February 2024, and the shares vesting on February 28, 2025 represent the final tranche of that grant. As agreed with the executive, 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 2023 PRSUs.</footnote>
        <footnote id="F2">Represents the closing price of the Company's common stock on February 28, 2025, the date of the tax withholding.</footnote>
        <footnote id="F3">Of the shares held as of February 28, 2025 after the vesting of the  2023 PRSUs, 14,123 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>
        <footnote id="F4">This forfeiture of shares for tax withholding purposes relates to the vesting on February 28, 2025 of performance based restricted stock units (&quot;2024 PRSUs&quot;) granted to the executive in May 2024. Of the 2024 PRSUs granted, 150% were determined to be earned by the executive pursuant to a resolution of the Axcelis Technologies, Inc. Compensation Committee on February 13, 2025, and half of the earned shares vested on February 28, 2025.  As agreed with the executive, 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 2024 PRSUs.</footnote>
        <footnote id="F5">Of the shares held as of February 28, 2025 after the vesting of the 2024 PRSUs, 11,985 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/ Lynnette C. Fallon, Attorney-in-Fact</signatureName>
        <signatureDate>2025-03-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
