Exhibit 5.1


Minnesota Mining and
  Manufacturing Company
3M Center
St. Paul, MN 55144

February 23, 2001


                 Re: Minnesota Mining and Manufacturing Company
                     $56,000,000 Floating Rate Notes Due 2040


            I am Assistant General Counsel of Minnesota Mining and Manufacturing
Company, a Delaware corporation (the "Company"), and as such I have acted as
counsel in connection with the issuance and sale by the Company of $56,000,000
Floating Rate Notes due 2040 (the "Securities") pursuant to an Underwriting
Agreement (the "Underwriting Agreement") and a Pricing Agreement (the "Pricing
Agreement"), both dated as of February 20, 2001, between the Company and UBS
Warburg LLC, offered pursuant to a Prospectus Supplement dated as of February
20, 2001. The Securities have been issued under an Indenture, dated as of
November 17, 2000, between the Company and a trustee (the "Indenture").

            In connection with the foregoing, I have examined, or am familiar
with, originals, or copies, certified or otherwise, identified to my
satisfaction, of such documents, corporate records and other instruments as I
have deemed necessary for the purpose of this opinion.

            Based upon the foregoing, I am of the opinion as follows:

            1.          The Company has been duly incorporated and is validly
                        existing as a corporation of good standing under the
                        laws of the State of Delaware; and

            2.          The Indenture has been duly authorized, executed and
                        delivered and constitutes a valid and binding agreement
                        of the Company in accordance with its terms, and the
                        Securities have been duly authorized, executed and
                        authenticated in accordance with the terms of the
                        Indenture and delivered in accordance with the
                        provisions of the Underwriting Agreement and the Pricing
                        Agreement and have been validly issued and constitute
                        valid and binding obligations of the Company in
                        accordance with their terms, in each case subject to
                        bankruptcy, insolvency, reorganization and other laws of
                        general applicability relating to or affecting the
                        enforcement of creditors' rights and to general equity
                        principles;




            This opinion is limited to the Federal laws of the United States and
the laws of the State of New York and, with respect to paragraph 1 above, the
General Corporate Laws of the State of Delaware (including the statutory
provisions and all applicable provisions of the Delaware Constitution and
reported judicial decisions interpreting the General Corporate Laws of the State
of Delaware) and I am expressing no opinions as to the effect of the laws of any
other jurisdiction. I am familiar with the proceedings heretofore taken by the
Company in connection with the authorization, registration, issuance and sale of
the Securities. I have, with your consent, relied as to factual matters on
certificates or other documents furnished by the Company or its officers and by
governmental authorities and upon such other documents and data that I have
deemed appropriate. I have assumed the authenticity of all documents submitted
to us as copies.

            I am aware that I am referred to under the heading "Legal Opinions"
in the Prospectus Supplement relating to the issuance of the Securities, and I
hereby consent to such use of my name therein and to the use of this opinion for
filing with the Securities and Exchange Commission (the "Commission") on the
Form 8-K. In giving this consent, I do not hereby admit that I am within the
category of persons whose consent is required under Section 7 of the Act or the
Rules and Regulations of the Commission promulgated thereunder.


                                      Very truly yours,


                                      /s/ Gregg M. Larson
                                      ------------------------------
                                      Gregg M. Larson
                                      Assistant General Counsel