FUEL CELL SYSTEM

PROBLEM TO BE SOLVED: To discharge impurities effectively even from a location near the inner side end part separated from the end part of a fuel cell where an exhaust port is located in a cell stack. SOLUTION: The fuel cell system is provided with a cell stack 10 which includes a plurality of unit cells 10A having a passage in which a fuel gas flows, an upper side passage 25 which is formed penetrating the unit cell 10A at the upstream side of the passage in respective unit cell and supplies the fuel gas to the passage, and a downstream side passage 5 which is formed penetrating the unit cell 10A at the downstream side of the passage of respective unit cell and in which reaction gas passing the unit cell flows out of the passage. The downstream side passage has an exhaust port on one of the end part side of the cell stack 10 and a reaction gas inlet port to introduce from the other end part side. Furthermore, it is provided with connection passages L3, L4 to connect the exhaust port and the reaction gas inlet port. Further, a gas drive means 1 to circulate the reaction gas discharged to the exhaust port to the reaction gas inlet port is provided at the connection passages L3, L4. COPYRIGHT: (C)2008,JPO&INPIT