A fuel cell includes a solid polymer electrolyte membrane, and a cathode separator and an anode separator sandwiching a solid polymer electrolyte membrane therebetween. The fuel cell includes an oxidant gas channel including a plurality of wave-shaped channel portions extending in a horizontal direction. Part of one of the plurality of wave-shaped channel portions that is disposed at the lower end in the vertical direction protrude downward from a planar region of electrode catalyst layers, i.e. a power generation region, in the vertical direction.