Polymer electrolyte fuel cell

A polymer electrolyte fuel cell is disclosed, comprising a MEA-gasket assembly including a MEA having a polymer electrolyte membrane, a pair of catalyst layers, and a pair of gas diffusion electrodes, and a pair of gaskets provided on peripheral portions of surfaces of both sides of the MEA with gaps between the gaskets and the gas diffusion electrodes; and a pair of electrically conductive separators disposed to sandwich the MEA-gasket assembly and provided with groove-shaped cell reaction gas passages on inner surfaces thereof, each of the cell reaction gas passages running sequentially on a corresponding gasket of the pair of gaskets, a corresponding gap of the gaps, a corresponding gas diffusion electrode of the pair of gas diffusion electrodes, the corresponding gap, and the corresponding gasket, wherein each of the gaps is partially closed by a closing means.