To efficiently use energy and sufficiently wet a solid polymer membrane in a system including a solid polymer type of fuel cell.

In a fuel cell system comprising a fuel cell 4, a hydrogen gas feeding source, an oxygen gas feeding source, and a water feeding source 5, wherein the fuel cell 4 where a negative pole portion, a solid polymer film as an electrode portion, and a positive pole portion are arranged between a pair of plates formed with groove portions for feeding the hydrogen gas or groove portions for feeding the oxygen gas is consisting of one unit or plural unit cells. Preferably forming a hollow type of space opened in one surface of the plates through a through hole expanding to a thickness direction in the plates located at the outermost portion of the fuel cell, at the same time continuously passing the space into the water feeding source 5. Further, in the bottom portion of the groove portion for feeding the hydrogen gas or the groove portions for feeding the oxygen gas of the plates, the through-hole is formed in parallel with the expanding direction of the groove portions.