Electrolyte membrane/electrode structure and fuel cell

The present invention provides an electrolyte membrane/electrode structure and a fuel cell. The electrolyte membrane/electrode structure (12) constituting the fuel cell (10) comprises a solid polymer electrolyte membrane (18), an anode side electrode (20) and a cathode side electrode (22) sandwiching the solid polymer electrolyte membrane (18). The anode side electrode (20) is provided with an electrode catalyst layer (20a) and a gas diffusion layer (20b) abutting on one side (18a) of the solid polymer electrolyte membrane (18) and exposing the outer circumference thereof in the shape of a frame, and the cathode side electrode (22) is provided with an electrode catalyst layer (22a) and a gas diffusion layer (22b) abutting on the other side (18b) of the solid polymer electrolyte membrane (18). A reinforcing sheet member (24) is arranged on the frame-shaped surface of the solid polymer electrolyte membrane (18) projecting from the outer circumference of the gas diffusion layer (20b).