FUEL CELL SYSTEM

A fuel cell system includes a gas liquid separator provided downstream of a humidifier in an oxygen-containing gas inlet channel, a fuel exhaust gas inlet channel for guiding a fuel exhaust gas containing liquid water discharged from a fuel cell stack to the gas liquid separator. The gas liquid separator performs gas liquid separation of both of an oxygen-containing gas humidified by the humidifier and the fuel exhaust gas containing the liquid water guided from the fuel exhaust gas inlet channel.