-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Kb5u49ZW7aZtkmuwZYtcFO6KVK3VoN5g5llkTdIq13Bj2aVyw5d3tSzlV6BtaV4l
 UxmdTjdthQxZ60IN3btMmQ==

<SEC-DOCUMENT>0000827054-10-000259.txt : 20101005
<SEC-HEADER>0000827054-10-000259.hdr.sgml : 20101005
<ACCEPTANCE-DATETIME>20101005180823
ACCESSION NUMBER:		0000827054-10-000259
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101001
FILED AS OF DATE:		20101005
DATE AS OF CHANGE:		20101005

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LITTLE MITCHELL R
		CENTRAL INDEX KEY:			0001181941

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21184
		FILM NUMBER:		101110325

	MAIL ADDRESS:	
		STREET 1:		2355 W CHANDLER BLVD
		CITY:			CHANDLER
		STATE:			AZ
		ZIP:			85224-6199

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MICROCHIP TECHNOLOGY INC
		CENTRAL INDEX KEY:			0000827054
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				860629024
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		2355 W CHANDLER BLVD
		CITY:			CHANDLER
		STATE:			AZ
		ZIP:			85224-6199
		BUSINESS PHONE:		480-792-7200

	MAIL ADDRESS:	
		STREET 1:		2355 WEST CHANDLER BLVD
		CITY:			CHANDLER
		STATE:			AZ
		ZIP:			85224-6199
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-10-01</periodOfReport>

    <issuer>
        <issuerCik>0000827054</issuerCik>
        <issuerName>MICROCHIP TECHNOLOGY INC</issuerName>
        <issuerTradingSymbol>MCHP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181941</rptOwnerCik>
            <rptOwnerName>LITTLE MITCHELL R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MICROCHIP TECHNOLOGY INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>2355 WEST CHANDLER BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>CHANDLER</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85224-6199</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, WW Sales and Appns.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7123</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-10-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5248</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5248</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5248</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one share of Microchip Technology Incorporated common stock.</footnote>
        <footnote id="F2">The restricted stock units will vest in full on November 15, 2014 as long as the individual remains a service provider through the vesting date and the Company achieves performance targets for operating profit in the quarter ended December 31, 2010.  Vested shares will be delivered to the reporting person upon vest.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Deborah L. Wussler, as Attorney-in-Fact</signatureName>
        <signatureDate>2010-10-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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