Patent ID: 8192884

Claim:
A fuel cell system comprising: a fuel cell; a fuel gas supply system that supplies a fuel gas to the fuel cell; and an oxidant gas supply system that supplies an oxidant gas to the fuel cell, wherein when operation end processing for the fuel cell system is started, a flow rate of the fuel gas supplied to the fuel cell is increased by a predetermined amount that is determined based on a temperature environment of the fuel cell system; when the temperature environment has a temperature equal to or lower than a predetermined temperature, the predetermined amount is determined based on a total value of at least a first fuel gas flow rate necessary for leaving the fuel gas in the fuel cell at the end of the operation end processing and a second fuel gas flow rate necessary for discharging water in the fuel cell to the outside during the operation end processing; and the predetermined amount is determined based on a total value obtained by further adding, to the first and second fuel gas flow rates, a third fuel gas flow rate necessary for the fuel cell to output, during the operation end processing, a current necessary for device operation during the operation end processing.