A fuel cell comprises a membrane electrode assembly including an electrolyte membrane and electrode layers arranged on each surface of the electrolyte membrane respectively, and first and second separators that are formed by processing a metal plate and are arranged so as to sandwich the membrane electrode assembly. At a position outside a position facing the membrane electrode assembly, the separators have an opening that constitutes a reaction gas flow path that is roughly perpendicular to a surface direction of the membrane electrode assembly. The first separator has a folded back part that is formed by folding back at least part of the metal plate of the position at which the opening is formed toward the membrane electrode assembly side along a boundary line on the membrane electrode assembly side of the opening as a fold line. The folded back part has a communication hole that allows communication between an internal flow path space and the reaction gas flow path, the internal flow path space being a space communicated with an end surface of the membrane electrode assembly and being formed between the folded back part and the first separator. The second separator does not have the folded back part.