A fuel cell includes a membrane electrode assembly and a metal separator. The membrane electrode assembly includes an electrolyte membrane, first and second electrodes, and a resin frame member. The resin frame member is provided on an outer peripheral portion of the membrane electrode assembly. The metal separator is stacked on the membrane electrode assembly in a stacking direction and includes a reactant gas channel, a reactant gas manifold, and a flat portion. The resin frame member of the membrane electrode assembly has an outer shape to be disposed further inward than the reactant gas manifold and includes a connection channel portion that is disposed outward from an electrode surface and that connects the reactant gas manifold and the reactant gas channel to each other. The flat portion is provided in contact with the connection channel portion.