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                                                                    EXHIBIT 10.4

                   SUPPLEMENTAL RETIREMENT BENEFIT AGREEMENT

                AGREEMENT between DIEBOLD, INCORPORATED, an Ohio corporation
(the "Company") and ROBERT W. MAHONEY (the "Executive"),                
        WITNESSETH:

                                   RECITALS

        A.  Executive is presently employed in a key executive
position as the Company's President. 
        
        B. The Company wishes to provide for the Executive a supplemental
pension benefit upon the terms and conditions set forth in this Agreement.  

        IT IS NOW THEREFORE agreed as follows:

        1.   DEFINITIONS.  For purposes of this Agreement, the following
        definitions shall apply:

        1.1     "Retirement Plan" shall mean the
        Diebold Incorporated Retirement Plan for Salaried Employees-Plan No.
        001.  

        1.2     "Committee" shall mean the Retirement Plan Committee as
        provided for in Article VIII of the Retirement Plan. 
 
        1.3     "Final Average Compensation" shall have the same
        meaning as set forth in the Retirement Plan except that until
        Executive has received compensation for at least five (5) consecutive
        calendar years, Final Average Compensation shall be computed by (a)
        aggregating all compensation paid to the Executive during his
        employment by the Company and (b) dividing the aggregate compensation
        by the number of months during which the Executive was paid and (c)
        multiplying the result by 12.


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        1.4     "Benefit Service" shall have the same meaning accorded to such
        words in the Retirement Plan for vesting purposes.  
        
        1.5    "Retirement Benefit" shall have the same meaning
        accorded to such words in the Retirement Plan.                 
        
        2.      SUPPLEMENTAL RETIREMENT BENEFIT 
         
        2.1     AMOUNT OF BENEFIT.  Upon termination of his employment with the
        Company for any reason, the Company agrees to pay to Executive a 
        Supplemental Retirement Benefit equal to the difference between (a) the 
        benefit he would be entitled to receive under the Retirement Plan if 
        his years of Benefit Service under the Plan were increased by eleven 
        (11) years, and (b) the actual Retirement Benefit he is entitled to 
        receive under the Retirement Plan.          

        2.2     COMPUTATION OF BENEFIT.  The Supplemental
        Retirement Benefit payable to the Executive hereunder shall be
        computed on the basis of the actuarial assumptions and optional forms
        of payment used for the computation of his Retirement Benefit under
        the Retirement Plan.    

        2.3     METHOD OF PAYMENT.  Such Supplemental Retirement Benefit shall 
        be paid to the Executive or to his beneficiary in the same manner and 
        at the same time as Retirement Benefits shall be paid under the 
        Retirement Plan. 

        3.     MISCELLANEOUS PROVISIONS        

        3.1     ASSIGNMENT.  This Agreement shall be binding upon the Company 
        and Executive and their respective successors and assigns provided, 
        however, that no rights of any kind under this Agreement shall, without 
        the written consent
        
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        of the Company, be transferrable or assignable by the
        Executive or any other person or be subject to alienation,
        encumbrance, garnishment, attachment, execution or levy of any
        kind.  
                 
        3.2     INTERPRETATION.  All questions of interpretation, construction 
        or application arising under this Agreement shall be decided by the 
        Committee whose decision shall be final and conclusive upon all 
        persons.  
        
        3.3     EXECUTIVE'S RIGHTS.  Benefits payable under this Agreement
        shall be a general unsecured obligation of the Company to be
        paid by the Company from its own funds.  Neither the Executive
        nor any beneficiary shall have any lien or security interest
        in any fund or assets of the Company provided, however, that
        the Company may, in its discretion, purchase an annuity
        contract or an insurance contract to discharge its obligations
        hereunder or create a reserve for the payment of such
        benefits.  
        
        3.4     GOVERNING LAW.  This Agreement shall be
        construed in accordance with the laws of the State of Ohio.
        
Executed this 8th day of April, 1987.
                                                           DIEBOLD, INCORPORATED

                                            By: ________________________________
                                                                       "Company"


                                            ____________________________________
                                                               Robert W. Mahoney
                                                                     "Executive"