The separator of which the region facing the MEA is a flat includes the first electrode facing plate and the second electrode facing plate. The separator includes the reaction gas supply manifold to which the reaction gas is supplied. The first electrode facing plate includes a plurality of reaction gas supply holes formed at the end of the cell-reaction region. The intermediate plate includes a plurality of reaction gas supply path slits that forms the reaction gas supply paths, wherein each of the reaction gas supply paths has one end connected to the reaction gas supply manifold and other end connected to at least one of the plurality of reaction gas supply holes.