A first separator has an outlet side first connection channel connecting a first fuel gas flow field and a fuel gas discharge passage, and a second separator includes an outlet side second connection channel connecting a second fuel gas flow field and the fuel gas discharge passage. The outlet side first connection channel and the outlet side second connection channel include outer passages and outer passages arranged in the same plane formed by facing the first separator and the second separator. The outer passages and the outer passages are formed alternately and independently in the same plane.