A fuel cell system (1A) comprises: a housing (2) having an intake vent (31) for introducing outside air into an internal space; a fuel cell (4) that is housed in the housing (2) and generates electricity by electrochemically reacting a fuel gas and an oxidizing agent gas; a diaphragm air supply unit (6) that is disposed in the housing (2), takes in air introduced through the intake vent (31) and supplies that air to the fuel cell (4); and a heating unit (30) that is disposed in the housing (2) and heats the air going into the air supply unit (6) from the intake vent (31).
