MEAs are formed in regions corresponding to openings provided in a substrate. Each MEA includes an electrolyte membrane, an anode catalyst layer, and a cathode catalyst layer. The substrate has a first gas-impermeable region and a second gas-impermeable region between adjacent MEAs. A third gas-impermeable region is provided between the first gas-impermeable region and the second gas-impermeable region. The third gas-impermeable region having conductive property constitutes a part of interconnector.