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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,
 VEyfrK+tX+Ng43ahSPzYKMOnC59VTTN3d/9Jny1H3ere78rI+Txv08h00a3Hhv2Y
 HNNuTLjpYLUER832/IGFLg==

<SEC-DOCUMENT>0000066740-05-000023.txt : 20050128
<SEC-HEADER>0000066740-05-000023.hdr.sgml : 20050128
<ACCEPTANCE-DATETIME>20050128144719
ACCESSION NUMBER:		0000066740-05-000023
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041231
FILED AS OF DATE:		20050128
DATE AS OF CHANGE:		20050128

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			3M CO
		CENTRAL INDEX KEY:			0000066740
		STANDARD INDUSTRIAL CLASSIFICATION:	CONVERTED PAPER & PAPERBOARD PRODS (NO CONTAINERS/BOXES) [2670]
		IRS NUMBER:				410417775
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3M CENTER
		STREET 2:		BLDG. 220-11W-02
		CITY:			ST PAUL
		STATE:			MN
		ZIP:			55144-1000
		BUSINESS PHONE:		6517332204

	MAIL ADDRESS:	
		STREET 1:		3M CENTER
		STREET 2:		BLDG. 220-11W-02
		CITY:			ST. PAUL
		STATE:			MN
		ZIP:			55144-1000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MINNESOTA MINING & MANUFACTURING CO
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ALVARADO LINDA G
		CENTRAL INDEX KEY:			0001122788

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03285
		FILM NUMBER:		05557690

	BUSINESS ADDRESS:	
		STREET 1:		ALVARADO CONSTRUCTION INC
		STREET 2:		P O BOX 4366
		CITY:			DENVER
		STATE:			CO
		ZIP:			80204
		BUSINESS PHONE:		7029041482

	MAIL ADDRESS:	
		STREET 1:		2140 LAKE PARK BOULEVARD
		CITY:			RICHARDSON
		STATE:			TX
		ZIP:			75080-2254
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>a5.xml
<DESCRIPTION>5
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2004-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000066740</issuerCik>
        <issuerName>3M CO</issuerName>
        <issuerTradingSymbol>MMM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001122788</rptOwnerCik>
            <rptOwnerName>ALVARADO LINDA G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1266 SANTA FE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80204</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4899</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3986</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Corporation</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The directly-held common stock holding reported in Table I includes shares acquired pursuant to 3M's Dividend Reinvestment Program in transactions exempt from Section 16.</footnote>
        <footnote id="F2">The indirectly-held common stock holding (by Corporation) reported on Table I includes deferred dividend reinvestment shares acquired pursuant to 3M's Director Compensation Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ George Ann Biros For: Linda G Alvarado</signatureName>
        <signatureDate>2005-01-28</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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