Patent ID: 7771854

Claim:
A fuel cell system comprising: a fuel cell operated for power generation by reaction of a fuel gas and an oxygen-containing gas, the fuel gas being supplied from a fuel supply channel to a fuel gas flow field in said fuel cell, the oxygen-containing gas being supplied from an oxygen-containing gas supply channel to an oxygen-containing gas flow field in said fuel cell, the fuel gas consumed in the power generation being discharged to a fuel discharge channel and the oxygen-containing gas consumed in the power generation being discharged to an oxygen-containing gas discharge channel; scavenging means for scavenging the fuel gas from a fuel gas channel including said fuel supply channel, said fuel gas flow field in said fuel cell, and said fuel discharge channel by supplying the oxygen-containing gas into said fuel gas flow field in said fuel cell such that the fuel gas is replaced by the oxygen-containing gas, and discharging the supplied oxygen-containing gas through said fuel discharge channel; containment means for containing the oxygen-containing gas in said fuel gas channel after scavenging by said scavenging means; pressure detection means provided in said fuel gas channel; and failure determination means for determining a failure when the pressure of the oxygen-containing gas detected by said pressure detection means has a predetermined value or less.