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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,
 EEJXHazx421BDo36/z0w1jnEXPHYmW8lPyE/qivMxHVW7nPzQ7BU1DvgtCf+e/GW
 zDjGoLiiyHkKlWmiUoD8/g==

<SEC-DOCUMENT>0000066740-05-000098.txt : 20050418
<SEC-HEADER>0000066740-05-000098.hdr.sgml : 20050418
<ACCEPTANCE-DATETIME>20050418154044
ACCESSION NUMBER:		0000066740-05-000098
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050412
FILED AS OF DATE:		20050418
DATE AS OF CHANGE:		20050418

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:			Smyth Margaret Mary
		CENTRAL INDEX KEY:			0001321591

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03285
		FILM NUMBER:		05756578

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		651 733 1110

	MAIL ADDRESS:	
		STREET 1:		PO BOX 33428
		CITY:			ST. PAUL
		STATE:			MN
		ZIP:			55133
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2005-04-12</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001321591</rptOwnerCik>
            <rptOwnerName>Smyth Margaret Mary</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 33428</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ST. PAUL</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55133</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VICE PRESIDENT &amp;CHF ACCTG OFF</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5326</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">A grant of 5,326 restricted shares vesting in increments of 1/3 on the 12th of April in the years 2006 through 2008.  The shares are subject to forfeiture under certain circumstances.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: George Ann Biros  For: Margaret M Smyth</signatureName>
        <signatureDate>2005-04-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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