a dmfc system which realizes appropriate temperature management on a methanol aqueous solution and on a dmfc with consideration given to the activity of methanol oxidation reaction between electrodes and suppression of degradation of solid polymer films . the fuel cell system according to the present invention comprises : a fuel cell which generates electric power by using liquid fuel ; a fuel feed unit which feeds the liquid fuel to the fuel cell ; an emission recovery unit which recovers emissions from the fuel cell ; and a heat medium feed unit which feeds a heat medium for cooling the emissions to the emission recovery unit . here , the heat medium cools the fuel cell .