EXHIBIT 5

July 2, 2003


Board of Directors
Eaton Corporation

Ladies and Gentlemen:

         I am furnishing this opinion for Eaton Corporation (the "Company") in
connection with the Registration Statement (the "Registration Statement") on
Form S-3 being filed with the Securities and Exchange Commission (the
"Commission") under the Securities Act of 1933, as amended, relating to the
offering from time to time, as set forth in the prospectus contained in the
Registration Statement (the "Prospectus") and as to be set forth in one or more
supplements to the Prospectus (each such supplement, a "Prospectus Supplement"),
of up to $250,000,000 aggregate amount of the Company's (i) debt securities (the
"Debt Securities"), (ii) warrants to purchase Debt Securities (the "Debt
Warrants"), (iii) preferred shares (the "Preferred Shares") and (iv) common
shares (the "Common Shares"). The Debt Warrants, the Debt Securities, the
Preferred Shares and the Common Shares are collectively referred to as the
"Securities". Any Debt Securities and Preferred Shares may be convertible into
or exchangeable for Common Shares or other Securities.

         The Debt Securities will be issued in one or more series and may be
either senior debt securities (the "Senior Securities") issued pursuant to an
Indenture (the "Senior Indenture") dated as of April 1, 1994 between the Company
and JPMorgan Chase Bank (formerly known as Chemical Bank), trustee (the "Senior
Trustee"), or subordinated debt securities (the "Subordinated Securities")
issued pursuant to an Indenture (the "Subordinated Indenture") to be entered
into between the Company and an institution identified therein as trustee (the
"Subordinated Trustee"). The Debt Warrants will be issued under one or more debt
warrant agreements (each, a "Debt Warrant Agreement") to be entered into between
the Company and a financial institution identified therein as warrant agent
(each, a "Warrant Agent").

         I have examined the resolutions of the Board of Directors of the
Company (the "Resolutions") authorizing the Indentures and the issuance,
offering and sale of the Securities, and I have examined such corporate records
of the Company and such other documents and certificates as I have deemed
necessary as a basis for the opinions hereinafter expressed.

         Based on the foregoing, and having regard for such legal considerations
as I have deemed relevant, I am of the opinion that, under the laws of the State
of New York (which governs the Senior Indenture and the Subordinated Indenture)
where appropriate and otherwise under the laws of the State of Ohio:

         1. The Senior Indenture has been duly authorized, executed and
delivered by the Company and constitutes a legally binding instrument of the
Company enforceable against the Company in accordance with its terms.




Board of Directors
Eaton Corporation
Page 2

         2. The Senior Securities (including Senior Securities issuable upon
conversion of or exchange for any Security or upon exercise of any Debt Warrant)
have been duly authorized and, when the final terms thereof have been duly
established and approved and when duly executed by the Company, in each case
pursuant to the authority granted in the Resolutions, and authenticated by the
Senior Trustee in accordance with the Senior Indenture and delivered to and paid
for by the purchasers thereof, will constitute legally binding obligations of
the Company entitled to the benefits of the Senior Indenture.

         3. The Subordinated Indenture has been duly authorized and, when
executed and delivered by the Company pursuant to the authority granted in the
Resolutions, and assuming due authorization, execution and delivery thereof by
the Subordinated Trustee, will constitute a legally binding instrument of the
Company enforceable against the Company in accordance with its terms.

         4. The Subordinated Securities (including Subordinated Securities
issuable upon conversion of or exchange for any Security or upon exercise of any
Debt Warrant) have been duly authorized and, when the final terms thereof have
been duly established and approved and when duly executed by the Company, in
each case pursuant to the authority granted in the Resolutions, and
authenticated by the Subordinated Trustee in accordance with the Subordinated
Indenture and delivered to and paid for by the purchasers thereof, will
constitute legally binding obligations of the Company entitled to the benefits
of the Subordinated Indenture.

         5. The Warrant Agreements have been duly authorized and, when executed
and delivered by the Company pursuant to the authority granted in the
Resolutions, and assuming due authorization, execution and delivery thereof by
the applicable Warrant Agent, will constitute legally binding instruments of the
Company enforceable against the Company in accordance with their respective
terms.

         6. The Warrants have been duly authorized and, when the final terms
thereof have been duly established and approved and when certificates
representing such Warrants have been duly executed by the Company, in each case
pursuant to the authority granted in the Resolutions, and when such certificates
have been countersigned by the applicable Warrant Agent in accordance with the
applicable Warrant Agreement and delivered to and paid for by the purchasers
thereof, such Warrants will constitute legally binding obligations of the
Company entitled to the benefits of the applicable Warrant Agreement.

         7. The Preferred Shares (including Preferred Shares issuable upon
conversion of or exchange for any Security) have been duly authorized and, when
the final terms thereof have been duly established and approved and certificates
representing such Preferred Shares have been duly executed by the Company, in
each case pursuant to the authority granted in the Resolutions, and when such
certificates have been delivered to and paid for by the purchasers thereof, and
when all corporate action necessary for issuance of such Preferred Shares has
been taken, including the adoption of a Certificate of Designations relating
thereto, such shares will be validly issued, fully paid and non-assessable.

         8. The Common Shares (including Common Shares issuable upon conversion
of or exchange for any Security) have been duly authorized and, when issued and
delivered pursuant to the authority granted in the Resolutions and against
payment therefor, will be validly issued, fully paid and non-assessable.




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Eaton Corporation
Page 3


         The opinions set forth above are subject, as to enforcement, to (i)
bankruptcy, insolvency (including, without limitation, all laws relating to
fraudulent transfers), reorganization, moratorium or other similar laws relating
to or affecting the enforcement of creditors' rights generally, (ii) general
equitable principles (regardless of whether enforcement is considered in a
proceeding in equity or at law) and (iii) provisions of law that require that a
judgment for money damages rendered by a court in the United States be expressed
only in United States dollars.

         I hereby consent to the use of this opinion as an exhibit to the
Registration Statement and to the use of my name under the heading "Legal
Opinions" in the Prospectus.

Very truly yours,


/s/ J. Robert Horst

J. Robert Horst
Vice President and
General Counsel