Patent ID: 8486578

Claim:
A membrane electrode assembly including a first electrode, a second electrode, and a solid polymer electrolyte membrane interposed between the first electrode and the second electrode, a surface area of the second electrode being larger than a surface area of the first electrode, the first electrode including a first catalyst layer and a first gas diffusion layer, the first catalyst layer contacting one surface of the solid polymer electrolyte membrane while allowing an outer circumference of the solid polymer electrolyte membrane in a frame shape to be exposed, the second electrode including a second catalyst layer and a second gas diffusion layer, the second catalyst layer contacting the other surface of the solid polymer electrolyte membrane, wherein a plane of the second gas diffusion layer is larger than a plane of the first gas diffusion layer; and a reinforcement sheet member is provided only on one side of a frame-shaped surface of the solid polymer electrolyte membrane, the frame-shaped surface extending outwardly from an outer circumferential end of the first gas diffusion layer, and wherein a surface of the reinforcement sheet member disposed opposite to the solid polymer electrolyte membrane is uncovered, wherein the second gas diffusion layer protrudes from an outer circumferential end of the second catalyst layer to cover the other surface of the solid polymer electrolyte membrane, and an adhesive layer is provided between the second gas diffusion layer protruding from the outer circumferential end of the second catalyst layer and the solid polymer electrolyte membrane.