-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 C18YmbrsIrXJbUmPVz9QOJlgmoDMIBXxO42SBEGs33ZOVItnO4s0QiMTlcsbCG7L
 tyhyC8O+Ifs/7wCLxLOvHQ==

<SEC-DOCUMENT>0001266457-10-000002.txt : 20100812
<SEC-HEADER>0001266457-10-000002.hdr.sgml : 20100812
<ACCEPTANCE-DATETIME>20100812193201
ACCESSION NUMBER:		0001266457-10-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100811
FILED AS OF DATE:		20100812
DATE AS OF CHANGE:		20100812

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KING ROBERT F
		CENTRAL INDEX KEY:			0001266458

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-11412
		FILM NUMBER:		101012648

	MAIL ADDRESS:	
		STREET 1:		C/O AMTECH SYSTEMS INC
		STREET 2:		131 SOUTH CLARK DRIVE
		CITY:			TEMPE
		STATE:			AZ
		ZIP:			85281

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMTECH SYSTEMS INC
		CENTRAL INDEX KEY:			0000720500
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				860411215
		STATE OF INCORPORATION:			AZ
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		131 S CLARK DR
		CITY:			TEMPE
		STATE:			AZ
		ZIP:			85281
		BUSINESS PHONE:		6029675146

	MAIL ADDRESS:	
		STREET 1:		131 SOUTH CLARK DRIVE
		CITY:			TEMPE
		STATE:			AZ
		ZIP:			85281

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	QUARTZ ENGINEERING & MATERIALS INC
		DATE OF NAME CHANGE:	19870715
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-08-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000720500</issuerCik>
        <issuerName>AMTECH SYSTEMS INC</issuerName>
        <issuerTradingSymbol>asys</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001266458</rptOwnerCik>
            <rptOwnerName>KING ROBERT F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O AMTECH SYSTEMS INC</rptOwnerStreet1>
            <rptOwnerStreet2>131 SOUTH CLARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>TEMPE</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85281</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Amtech Systems, Inc. $.01 par value common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.695</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Amtech Systems, Inc. Non-Employee Director Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.695</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-08-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-07-08</value>
            </exerciseDate>
            <expirationDate>
                <value>2015-07-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Amtech Systems, Inc. $.01 par value common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Price omitted because the derivative exercised is a granted stock option.</footnote>
        <footnote id="F2">This is the number of derivative securities, with the same terms and conditions, following the reported transaction. Total of all derivative securities, with different terms and conditions, held following the reported transaction is 25,000.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Robert T. Hass on behalf of Robert F. King by Power of Attorney</signatureName>
        <signatureDate>2010-08-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
