A fuel cell comprises a cathode catalyst layer and an anode catalyst layer disposed on each surface of an electrolyte membrane, an oxidant gas passage facing the cathode catalyst layer, and a fuel gas passage facing the anode catalyst layer. The cathode catalyst layer contains a metal catalyst. In a region (A), in which the differential electric potential between the cathode catalyst layer and the electrolyte membrane is larger than in another region, the metal catalyst content of the cathode catalyst layer or the specific surface area of the metal catalyst in the form of minute particles is increased, and thus a deterioration in electric power generation efficiency caused by melting of the metal catalyst due to the large differential electric potential is prevented.