A fuel cell supplies power to a load under nominal conditions. A method for using the fuel cell comprises at least one regeneration step of the performances of the fuel cell by temporarily lowering its temperature below the nominal operating temperature. The regeneration step, performed during a preset time, can be triggered periodically or when the voltage at the terminals of the fuel cell or the fuel cell temperature is lower than a threshold. The performances of the fuel cell, in particular its voltage, can thereby be maintained substantially constant during long periods of use.