A fuel cell includes a membrane electrode assembly constituted of an electrolyte membrane and an electrode layer, a frame portion disposed along an outer periphery of the membrane electrode assembly, and separators that include gas flow passages to supply the membrane electrode assembly with fuel gas, wherein the membrane electrode assembly is interposed by a pair of the separators, and the separators include adhesion regions bonded to the frame portion via an adhesive, and reduced portions where distances between the separators and the frame portion are shorter than distances between the separators and the frame portion at other adhesion regions in the adhesion regions.