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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,
 AsBR/Fcsouebmy5kDBagT4EYGF8ZvU7GgsA58spZVFz/xPFIJHuzeeLA66HFvxY/
 39rfZt4Bt+OWocZJPBBRig==

<SEC-DOCUMENT>0001102934-03-000051.txt : 20031103
<SEC-HEADER>0001102934-03-000051.hdr.sgml : 20031103
<ACCEPTANCE-DATETIME>20031103151625
ACCESSION NUMBER:		0001102934-03-000051
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031103
FILED AS OF DATE:		20031103

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CABOT MICROELECTRONICS CORP
		CENTRAL INDEX KEY:			0001102934
		STANDARD INDUSTRIAL CLASSIFICATION:	ABRASIVE ASBESTOS & MISC NONMETALLIC MINERAL PRODUCTS [3290]
		IRS NUMBER:				364324765
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		870 NORTH COMMONS DRIVE
		CITY:			AURORA
		STATE:			IL
		ZIP:			60504
		BUSINESS PHONE:		6303755461

	MAIL ADDRESS:	
		STREET 1:		870 N COMMONS DR
		CITY:			AURORA
		STATE:			IL
		ZIP:			60504

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NOGLOWS WILLIAM P
		CENTRAL INDEX KEY:			0001201094

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30205
		FILM NUMBER:		03972886

	BUSINESS ADDRESS:	
		STREET 1:		204 OCEAN AVE
		CITY:			MARBLEHEAD
		STATE:			MA
		ZIP:			01945
		BUSINESS PHONE:		7816317893

	MAIL ADDRESS:	
		STREET 1:		204 OCEAN AVE
		CITY:			MARBLEHEAD
		STATE:			MA
		ZIP:			01945
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>c0001201094d20031103f3f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>3</documentType><periodOfReport>2003-11-03</periodOfReport><noSecuritiesOwned>0</noSecuritiesOwned><issuer><issuerCik>0001102934</issuerCik><issuerName>CABOT MICROELECTRONICS CORP</issuerName>        <issuerTradingSymbol>CCMP</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001201094</rptOwnerCik><rptOwnerName>NOGLOWS WILLIAM P</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>C/O CABOT MICROELECTRONICS CORPORATION</rptOwnerStreet1><rptOwnerStreet2>870 COMMONS DRIVE</rptOwnerStreet2><rptOwnerCity>AURORA</rptOwnerCity><rptOwnerState>IL</rptOwnerState><rptOwnerZipCode>60504</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Chairman, President &amp; CEO</officerTitle><otherText></otherText></repo
rtingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>12653</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable></derivativeTable><footnotes></footnotes><ownerSignature><signatureName>H. Carol Bernstein</signatureName><signatureDate>2003-11-03</signatureDate></ownerSignature></ownershipDocument>

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