Patent ID: 7659024

Claim:
A fuel cell comprising: a membrane electrode assembly which is a composite member of a polyelectrolyte membrane, catalytic layers placed so as to sandwich the polyelectrolyte membrane, and gas diffusion layers placed outside the catalytic layers, respectively, and in which anode and cathode electrodes are formed; and a pair of separators in which gas-passage groove portions are so formed that their surfaces are brought into contact with the gas diffusion layers to form a gas passage, and which are so placed as to sandwich the membrane electrode assembly, wherein in each of the separators, the gas passage comprises a plurality of generally linear passage portions disposed generally in parallel to one another, and a plurality of bent passage portions which make end portions of the linear passages communicated with end portions of their adjacent linear passage portions, where the gas-passage groove portions are formed so as to be communicative from a gas feed port to a discharge port, and wherein in inner wall surfaces of the gas-passage groove portions constituting each of the linear passage portions, water-retaining groove portions for retaining inside thereof at least part of water generated in the gas passage are formed in such a grooved configuration as to be substantially continuous along the linear passage portion, and so as not to communicate with the discharge port.