FUEL CELL SYSTEM

PROBLEM TO BE SOLVED: To provide a fuel cell system capable of preventing reverse flow of water staying inside a fuel cell stack by a simple method. SOLUTION: When power generation is stopped, a control part 30 closes exhaust passage opening and closing valves 72, 82 and opens circulation passage opening and closing valves 78, 88. Thereby, the gas which is going to enter into an anode 32 and a cathode 34 from a fuel exhaust passage 70 and an air exhaust passage 80 is stopped by the exhaust passage opening and closing valves 72, 82 and passes through a fuel circulation passage 76 and an air circulation passage 86 opened and reaches a fuel supply passage 74 and an air supply passage 84. Furthermore, this gas is supplied to the anode 32 and the cathode 34 from the fuel supply passage 74 and the air supply passage 84. Thereby, reverse flow of water staying inside the fuel cell stack can be prevented by a simple method. COPYRIGHT: (C)2009,JPO&INPIT