Patent ID: 7749623

Claim:
A method of controlling a fuel cell system, the method comprising: supplying a hydrogen-containing fuel gas to an anode of a fuel cell using a fuel gas supply line; supplying an oxidant gas to a cathode of the fuel cell using an oxidant gas supply line; generating electricity by connecting an external load between the anode and the cathode; stopping the generating by disconnecting the external load, connecting a resistor between the anode and the cathode, stopping the supplying of the oxidant gas to the cathode to cause a potential at the cathode to drop, stopping the supplying of the hydrogen-containing fuel gas to the anode after the potential at the cathode drops to a potential value equal to or lower than a potential value at which hydrogen evolution starts, and evolving hydrogen at the cathode from the hydrogen-containing fuel gas which has been supplied to the anode; and filling a space leading to the cathode and a space leading to the anode with the hydrogen-containing fuel gas after the stopping the generating.