POLYMER ELECTROLYTE FUEL CELL

Polymer electrolyte fuel cell has hydrogen ion conductive polymer electrolyte film, anode and cathode, anode side conductive separator and cathode side conductive separator. Polymer electrolyte fuel cell has a hydrogen ion conductive polymer electrolyte film, an anode and a cathode sandwiching the electrolyte film, an anode side conductive separator having a gas supply path which supplies fuel gas to the anode and a cathode side conductive separator having a gas supply path which supplies oxidizing gas to the cathode. The separators comprise an acid resistant conductive air-tight elastic body which comprises a polymer elastic body based on a polyisobutylene and an ethylene-propylene random copolymer, and an inorganic conductive material. The polyisobutylene is of formula (I): [Image] X and Y : polymerizable functional groups; m : the number of repeat units of isobutylene oligomer and is >= 1; and the ethylene-propylene random copolymer is of formula (II): [Image] X and Y : polymerizable functional groups; l, m and n : integers of >= 1.