Fuel cell

A polymer electrolyte fuel cell (10) includes an electrode (17, 14) including a catalyst layer (15, 12) and a diffusion layer (16, 13). The catalyst layer (15, 12) is divided into a plurality of portions including an upstream portion and a downstream portion along a reactant gas flow direction. The upstream portion of the catalyst layer (15, 12) has a structure for preventing a drying-up of the cell, and the downstream portion of the catalyst layer (15, 12) has a structure for preventing a flooding of the cell. A structure of the diffusion layer (16, 13) also may differ between at the upstream portion and at the downstream portion.