Patent ID: 7297432

Claim:
A fuel cell comprising: an electrode assembly sandwiched between a first separator having an inner surface and a second separator having an inner surface, the electrode assembly being composed of an electrolyte membrane sandwiched between an anode electrode and a cathode electrode; an outer seal member sandwiched between the first and second separators at a position surrounding an outer periphery of the electrode assembly, wherein the outer seal member contacts the inner surface of both of the first and second separators; an inner seal member sandwiched between the first separators and the electrolyte membrane, wherein the electrolyte membrane has a first outer surface that faces the inner surface of the first separator and an opposed second outer surface that faces the inner surface of the second separator, wherein the inner seal member contacts the inner surface of the first separator and the first outer surface of the electrolyte membrane; and a backing member sandwiched between the second separator and the electrolyte membrane, wherein the backing member contacts the inner surface of the second separator and the second outer surface of the electrolyte membrane; wherein, there is a step formed on the second separator at a position located between the outer seal member and the backing member contact the inner surface of the second separator.