A fuel cell (10) includes a membrane-electrode assembly (12), a first separator (14), and a second separator (16). The second separator (16) has a fuel gas flow field (32) connected to a fuel gas supply passage (24a) and a fuel gas discharge passage (24b). The fuel gas flow field (32) includes a plurality of corrugated flow grooves (32a) and a flat flow field (32b). The corrugated flow grooves extend in the horizontal direction, respectively, and are arranged in the direction of the gravity. The flat flow field is provided within a power generation area, at the lowermost position in the direction of the gravity, and extends in the horizontal direction.