NOVELTY - The device has a mixing tank (23) for mixing a fuel with a fluid to produce a diluted fuel. A fuel cell generates electricity by utilizing the diluted fuel. The diluted fuel is circulated between the fuel cell and the mixing tank through a flow path. A filter unit (34) removes metal ions from a methanol aqueous solution, where the solution is supplied to direct methanol fuel cell device (DMFC) stack. Quantity of the high-concentration methanol flowing from a fuel cartridge into the tank and water flowing from a water recovery tank into the mixing tank are adjusted.    USE - Used as a power source for electronic apparatus (claimed) such as personal digital assistant (PDA) device and portable computer.    ADVANTAGE - The fuel cell device does not require dedicated case for housing the filter unit and special coupling units for connecting the filtering units to flow paths, thus reducing number of parts for configuring the device and installation space of the device. The quantity of the high-concentration methanol that flows from the fuel cartridge into the mixing tank and water which flows from the water recovery tank into the mixing tank are adjusted so that the concentration of the methanol aqueous solution is controlled to a value, thus maintaining performance of electricity generation. The methanol aqueous solution from which metal ions are removed by the filter unit is supplied to the DMFC stack, thus restricting flow of the methanol aqueous solution containing metal ions into the DMFC stack, thus preventing reduction of the generation efficiency due to metal ions.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for an electronic apparatus comprising a body and a fuel cell device.    DESCRIPTION OF DRAWING(S) - The drawing shows a section view of a mixing tank of a fuel cell device.    Mixing tank (23)    Filter unit (34)    Fuel flow path (38)    Recovery flow path (40)    Discharge flow path (41)    Tank body (63)    Cover unit (64)    Support projections (65)    Pressing unit (66)    Spring units (67)