-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 MWtiD3ZzTWwmMOMsRKT/bVkKdALPDykeYEKWjyd4D+55Qg2jwSCVNRIeUxqsTFDh
 yaD+oBXGsWZYKeaaSGHUlA==

<SEC-DOCUMENT>0001266457-10-000029.txt : 20101210
<SEC-HEADER>0001266457-10-000029.hdr.sgml : 20101210
<ACCEPTANCE-DATETIME>20101210171730
ACCESSION NUMBER:		0001266457-10-000029
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101209
FILED AS OF DATE:		20101210
DATE AS OF CHANGE:		20101210

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:		101245855

	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>2010-12-09</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>2010-12-09</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>9.05</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Amtech Systems, Inc. $.01 par value common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.8822</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</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>9.05</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-12-09</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>2009-03-02</value>
            </exerciseDate>
            <expirationDate>
                <value>2016-03-02</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 transaction is a grant of a 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 20,000.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Robert T. Hass on behalf of Robert F. King by Power of Attorney</signatureName>
        <signatureDate>2010-12-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
