Patent ID: 7201987

Claim:
A fuel cell unit comprising a membrane electrode assembly, and a pair of separators which sandwiches the membrane electrode assembly, wherein the membrane electrode assembly comprises: a solid polymer electrolyte membrane; first and second gas diffusion electrodes which are disposed respectively on opposite sides of the solid polymer electrolyte membrane, the first gas diffusion electrode having a peripheral edge region; and a frame-shaped first seal member having a rectangular cross section which is disposed so as to cover said peripheral edge region only of the first gas diffusion electrode and covers and supports a peripheral part of the solid polymer electrolyte membrane that extends over the first gas diffusion electrode and the first seal member; and a second seal member having a circular cross section which is disposed on the peripheral part of the solid polymer electrolyte membrane, wherein the second seal member has a shape different from a shape of the frame-shaped first seal member, a dimension of the pair of the separators is larger than a dimension of the membrane electrode assembly; and a third seal member is sandwiched between the separators, wherein the first and second gas diffusion electrodes are substantially the same size and coextensive relative to each other.