A fuel cell includes a membrane electrode assembly (101); a first gas diffusion layer (104) having a first raised portion (104a); an anode side separator (102); a second gas diffusion layer (105) having a second raised portion (105a); and a cathode side separator (103). A fuel gas passage (102b) formed by a first groove (102a) and the first raised portion (104a) has a first cross section (A1), while an oxidation gas passage (103b) formed by a second groove (103a) and the second raised portion (105a) has a second cross section (A2). The first raised portion (104a) and the second raised portion (105a) are different from each other in scale, forming the first cross section (A1) and the second cross section (A2) different from each other.