An electrode structure 15 is received in a joint portion of frames 13, 14. A first gas diffusion layer 19 and a first gas passage forming member 21 are arranged on a first surface of the electrode structure 15. A second gas diffusion layer 20 and a second gas passage forming member 22 are formed on a second surface of the electrode structure 15. A separator 23 is joined with a surface of the frame 13 and a surface of the gas passage forming member 21. A separator 24 is joined with a surface of the frame 14 and a surface of the gas passage forming member 22. A water passage 28 is formed between a flat plate 25 of the gas passage forming member 22 and the separator 24. The water passage 28 has a depth set to a value smaller than depth of a gas passage T2 of the gas passage forming member 22. Generated water is introduced from the gas passage T2 of the gas passage forming member 22 to the water passage 28 through capillary action via communication holes 29. The generated water in the water passage 28 is moved to a downstream side of the water passage 28 by pressure caused by oxidization gas. This prevents corrosion of the cathode side electrode catalyst layer and improves durability of the anode side gas passage forming member. As a result, a fuel cell capable of preventing decrease of power generation is provided.