Patent ID: 7618728

Claim:
A fuel cell system comprising: fuel gas supply means for supplying a fuel gas; oxidant gas supply means for supplying an oxidant gas; a fuel cell to which the fuel gas and the oxidant gas are supplied for generation of electricity; an idle stop means for stopping generation of electricity by the fuel cell to perform an idle stop; and an unstable state detection means for detecting whether the generation of electricity by the fuel cell is unstable, wherein if the unstable state detection means detects that the generation of electricity by the fuel cell is unstable, the idle stop by the idle stop means is prohibited so that the cell continues to generate electricity; and temperature sensing means for detecting an operation temperature of the fuel cell, wherein the unstable state detection means carries out a detection in accordance with the operation temperature of the fuel cell that is detected by the temperature sensing means and a first predetermined temperature under which generation of electricity by the fuel cell becomes unstable.