the fuel cell device is provided with : an electricity - generating unit having a fuel electrode , an air electrode , and an electrolyte film sandwiched between the fuel electrode and the air electrode ; a hydrogen - generating member that , by means of an oxidation reaction with water , generates hydrogen for supplying to the fuel electrode of the aforementioned electricity - generating unit ; a heater that heats the hydrogen - generating member ; a temperature sensor that detects the temperature of the hydrogen - generating member ; and a temperature control unit that controls the temperature of the hydrogen - generating member in response to the detection results of the temperature sensor . the temperature control unit stops the passage of electricity through the heater when it has been determined that the temperature of the hydrogen - generating member is at least a predetermined temperature .