A fuel cell includes a membrane electrode assembly and separators which are stacked. A fuel gas channel allows a fuel gas to flow along a surface of one of a pair of electrodes. An oxidant gas channel allows an oxidant gas to flow along a surface of another of a pair of electrodes. A channel width of the oxidant gas channel in a central portion of the oxidant gas channel in a channel width direction is larger than a channel width of the oxidant gas channel in both end portions of the oxidant gas channel in the channel width direction. A channel width of the fuel gas channel in a central portion of the fuel gas channel in a channel width direction is smaller than a channel width of the fuel gas channel in both end portions of the fuel gas channel in the channel width direction.