A power generation cell includes a membrane electrode assembly and first and second metal separators sandwiching the membrane electrode assembly. Ridge members are formed integrally on the second metal separator, and these ridge members contact a first seal member of the first metal separator under pressure to form an inlet connection channel and an outlet connection channel. The coolant supply passage and the coolant flow field are connected through the inlet connection channel and the coolant discharge passage and the coolant flow field are connected through the outlet connection channel.