Fuel cell seals

A fuel cell (10) includes a membrane electrode assembly (12) and first and second separators (14, 16) for sandwiching the membrane electrode assembly (12). A serpentine oxygen-containing gas flow field (36) is formed on a surface (14a) of the first separator (14). A seal member (50) is provided around the oxygen-containing gas flow field (36), i.e., around the anode (28). Filling seals (54) are provided in a clearance (52) between the seal member (50) and the cathode (30) at positions where the leakage of an oxygen-containing gas is likely to occur.