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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 FAM7rl/tedwKDdo4AGN5vLTT7zWtHSEyMIASmDOhtqmDVWPe8KpDBH54ABy3rPRN
 6u0FiTW2xroPTrYeO+aGJQ==

<SEC-DOCUMENT>0000950145-08-000046.txt : 20080407
<SEC-HEADER>0000950145-08-000046.hdr.sgml : 20080407
<ACCEPTANCE-DATETIME>20080407161810
ACCESSION NUMBER:		0000950145-08-000046
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080403
FILED AS OF DATE:		20080407
DATE AS OF CHANGE:		20080407

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EMCORE CORP
		CENTRAL INDEX KEY:			0000808326
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				222746503
		STATE OF INCORPORATION:			NJ
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		145 BELMONT DRIVE
		CITY:			SOMERSET
		STATE:			NJ
		ZIP:			08873
		BUSINESS PHONE:		7322719090

	MAIL ADDRESS:	
		STREET 1:		145 BELMONT DRIVE
		CITY:			SOMERSET
		STATE:			NJ
		ZIP:			08873

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HOU HONG Q
		CENTRAL INDEX KEY:			0001156899

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22175
		FILM NUMBER:		08743026

	BUSINESS ADDRESS:	
		STREET 1:		EMCORE CORP
		STREET 2:		145 BELMONT DRIVE
		CITY:			SOMERSET
		STATE:			NJ
		ZIP:			08873
		BUSINESS PHONE:		7372719090
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-04-03</periodOfReport>

    <issuer>
        <issuerCik>0000808326</issuerCik>
        <issuerName>EMCORE CORP</issuerName>
        <issuerTradingSymbol>EMKR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001156899</rptOwnerCik>
            <rptOwnerName>HOU HONG Q</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2015 W. CHESTNUT ST.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ALHAMBRA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91803</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO &amp; President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.67</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-04-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>150000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-04-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>150000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>150000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option vests in 4 equal installments on the first 4 anniversaries of the date of grant.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Hong Q. Hou</signatureName>
        <signatureDate>2008-04-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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