Patent ID: 8911917

Claim:
A fuel cell formed by stacking a membrane electrode assembly and a separator in a stacking direction, the membrane electrode assembly including a pair of electrodes, and an electrolyte membrane interposed between the electrodes, a reactant gas flow field for supplying a reactant gas along an electrode surface being formed in the separator, a reactant gas supply passage and a reactant gas discharge passage extending through the fuel cell for supplying the reactant gas in the stacking direction, the fuel cell comprising: an inlet buffer connecting the reactant gas supply passage and the reactant gas flow field and an outlet buffer connecting the reactant gas discharge passage and the reactant gas flow field, wherein the inlet buffer includes a first inlet buffer area adjacent to the reactant gas supply passage and a second inlet buffer area adjacent to the reactant gas flow field; the outlet buffer includes a first outlet buffer area adjacent to the reactant gas discharge passage and a second outlet buffer area adjacent to the reactant gas flow field; the first inlet buffer area is deeper than the second inlet buffer area in the stacking direction, and the first outlet buffer area is deeper than the second outlet buffer area in the stacking direction; and the first inlet buffer area and the first outlet buffer area have different surface areas.