A cell structure of a fuel cell, which is provided with: a membrane electrode assembly (M) wherein an electrolyte membrane (1) is held between a pair of electrode layers (2, 3); a frame (4) that is arranged on the outer peripheral portion of the electrolyte membrane (1); a separator (5) that forms a gas channel (G) between itself and the membrane electrode assembly (M); a sealing member (6) that is arranged closer to the outer periphery than the gas channel (G); and a porous metal body (23) that has gas permeability and is arranged on the surfaces of the electrode layers (2, 3). The porous metal body (23) is provided, on the outer periphery thereof, with an extending portion (23A) that extends beyond the electrode layer (2). The frame (4) is provided with an embedding portion (40) in which the extending portion (23A) of the porous metal body (23) is embedded. A holding means, which holds the extending portion (23A) of the porous metal body (23), is provided between the separator (5) and the embedding portion (40).