Patent ID: 8722219

Claim:
A fuel cell stack comprising a plurality of stacked unit fuel cells and end holding members for interposing and holding the stacked unit fuel cells from both sides thereof along a direction in which the unit fuel cells are stacked, wherein: each unit fuel cell has: a membrane electrode assembly in which an anode and a cathode interpose an electrolyte membrane; and a pair of separators which respectively closely contact the anode and the cathode of the membrane electrode assembly, so as to respectively form reaction gas passages between one of the separators and the anode, and between the other separator and the cathode, and with respect to each of the reaction gas passage facing toward the anode and the reaction gas passage facing toward the cathode: a gas supply passage and a gas discharge passage are formed penetrating through the stacked unit fuel cells and one of the end holding members in a manner such that they communicate with the reaction gas passage of each unit fuel cell; and a drainage passage is also formed penetrating through the stacked unit fuel cells and said one of the end holding members, wherein an end of the drainage passage and an end of the gas discharge passage on the side of the other end holding member are joined to each other, wherein the drainage passage, while within the fuel cell stack, is formed outside of the gas discharge passage, the drainage passage being separated from the gas discharge passage by a sealing member provided on at least one of the separators.