NOVELTY - The device has a reformer (2) with a burner (11), a fuel cell (3) formed of an anode (4) and a cathode (5), and a hydrogen buffer-tank (6). A palladium and/or polymer based membrane (7) is placed between the reformer and the anode. A control unit (14) is connected to valves (15, 16). The hydrogen buffer-tank is inserted between the anode and a starting burner (12) positioned in the upstream of the reformer.    USE - Used in a motor vehicle for the production of electricity (claimed) in the form of direct current, from a fuel such as hydrogen, produced from methanol or gasoline, and a comburent such as oxygen, to supply an electric engine for assuring the propulsion of the vehicle.    ADVANTAGE - The utilization of the palladium and/or polymer based membrane between the reformer and the fuel cell permits to store pure hydrogen and reduce the volume of the hydrogen buffer-tank by 25 percent. The device allows to optimize the supply of hydrogen from the fuel cell by distributing the enriched hydrogen flow between the reformer and the cell according to the operation phases of the device. The hydrogen buffer-tank provides the quantity of hydrogen necessary for the production of electricity, so that the fuel cell is supplied uninterruptedly with hydrogen during the transient of starting of the reformer. The membrane enables the propulsion of the vehicle in which the volume of the engine is limited. The device also allows to use quasi-pure hydrogen in order to avoid over-stoichiometry for the hydrogen at the input of the cell and reduce the quantity of required hydrogen to about 23 percent. The control unit opens the two valves to supply the fuel cell directly with hydrogen, during the starting transient phase of the reformer, as long as the reformer is cool and it cannot produce reformat. The device provides thermal energy to the reformer to reduce the time of provision. The buffer-tank supplies hydrogen not only to the cell but also to the starting, during the transient. The starting burner permits to support the heating of the reformer and to reduce the emissions of pollutants which would result from the combustion of a liquid fuel stored in a reservoir. The control unit, when the reformer does not operate, opens one valve permitting direct supply of the fuel cell and closes the other to provide maximum output. The device presents a supply architecture enabling to reduce the time of heating of the reformer such that it produces rapid reformats.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for production of electricity using a fuel cell device.    DESCRIPTION OF DRAWING(S) - The drawing shows a fuel cell device.    Reformer (2)    Fuel cell (3)    Anode (4)    Cathode (5)    Hydrogen buffer-tank (6)    Palladium and/or polymer based membrane (7)    Burner (11)    Starting burner (12)    Control unit (14)    Valves (15, 16)