NOVELTY - Fuel cell system for motor vehicle, comprises fuel cell (2) for power generation from oxidator- and fuel gas with an anode inlet (4), an anode outlet (5), a cathode inlet (6), a cathode outlet (7) and with supply terminal, and a reformer (3) for fuel generation from oxidator gas and fuel with catalyst, a fuel inlet, oxidator inlet and with fuel outlet. A fuel gas line is connected with the fuel inlet and the anode inlet. An oxidator guiding device is used for providing the fuel cell and the reformer. A fuel-guiding device is used for providing the reformer with fuel.    USE - For motor vehicle.    ADVANTAGE - Fuel cell system avoids risk of damages of the anode side of the fuel cell, produced by the temperature emerging from the burning down of the soot particles. Avoids the disturbances of the reforming- and fuel cell process, produced by the reaction products emerging from the burning down of the particles.    DETAILED DESCRIPTION - The fuel cell system for motor vehicle, comprises fuel cell (2) for power generation from oxidator- and fuel gas with an anode inlet (4), an anode outlet (5), a cathode inlet (6), a cathode outlet (7) and with supply terminal, and a reformer (3) for fuel generation from oxidator gas and fuel with catalyst, a fuel inlet, oxidator inlet and with fuel outlet. A fuel gas line is connected with the fuel inlet and the anode inlet. An oxidator guiding device is used for providing the fuel cell and the reformer. A fuel-guiding device is used for providing the reformer with fuel. Sensors are used for determining the temperature of the fuel cell and the reformer. A control system is used for operating the oxidator- and fuel-guiding device. The control system is arranged and carries out a regeneration process for the regeneration of the catalyst in the power down of the fuel cell system. The control system operates the reformer as a burner during the regeneration process. The control system reduces or stops the burner operation of the reformer during the regeneration process, when the temperature of the reformer lies above a pre-determined reformer threshold temperature and/or increases or starts the burner operation of the reformer during the regeneration process, when the temperature of the fuel cell lies below the fuel cell threshold temperature and/or the temperature of the reformer lies below the reformer threshold temperature. An INDEPENDENT CLAIM is included for a method for power down of a fuel cell system.    DESCRIPTION OF DRAWING(S) - The figure shows a fuel cell system for motor vehicle:    Fuel cell; (2)    Reformer; (3)    Anode inlet; (4)    Anode outlet; (5)    Cathode inlet; (6)    Cathode outlet. (7)