Solid polymer electrolyte fuel cell and non-humidifying operating method therefor

A fuel cell comprising a fuel cell unit composed of a solid polymer ion exchange membrane interposed between an anode electrode and a cathode electrode, and separators for supporting said fuel cell unit interposed therebetween, said fuel cell further comprising:

• said solid polymer ion exchange membrane having a thickness set to be within a range of 20 μm to 60 μm;
• a fuel gas flow passage for supplying, in a non-humidifying manner, a fuel gas from a first side of said solid polymer ion exchange membrane to said anode electrode;
• and
• an oxygen-containing gas flow passage for supplying, in a non-humidifying manner, an oxygen-containing gas from a second side of said solid polymer ion exchange membrane to said cathode electrode, wherein:
• a portion of said fuel gas flow passage, which is disposed adjacent to an fuel gas inlet, and a portion of said oxygen containing gas flow passage disposed adjacent to an oxygen containing gas outlet are arranged so as to allow diffusion of moisture from the cathode electrode to the anode electrode, with said solid polymer ion exchange membrane intervening therebetween.