Patent ID: 8647782

Claim:
A fuel cell system comprising: a fuel cell that generates power when fuel gas is supplied to an anode and oxidant gas is supplied to a cathode; an electrical load that consumes electric power generated by the fuel cell; an idling stop control means for setting the fuel cell to an idling stop state by, in response to a predetermined condition being satisfied during idling power generation, decreasing both a supplied amount of oxidant gas to the fuel cell and generated electric current produced from the fuel cell to less than during the idling power generation, within a range greater than zero; a discharge valve provided in an anode system through which gas supplied to the anode and gas discharged from the anode flows; a dilution means for diluting fuel gas discharged from inside the anode system by opening the discharge valve, with oxidant gas serving as a dilution gas; and a discharge valve control means for determining whether there is a necessity to discharge residue inside of the anode system during the idling power generation and during the idling stop, and for opening the discharge valve over a predetermined time period in a case of there being a necessity, wherein the discharge valve control means shortens a valve open time of the discharge valve during the idling stop to less than a valve open time of the discharge valve during the idling power generation.