To provide a technique for unifying the cooling system of a fuel cell and the cooling system of an electric driving system, and making a cooling medium circulate through both the cooling systems using identical same pump.

Cooling water from a first radiator and a second radiator connected in series is branched into two at a branching point 106, one of them is supplied from an electric driving system 107 to a fuel cell 111, and the other is supplied from a flow volume distribution control valve 108 to the fuel cell 111. Cooling water cooled at the radiator is supplied to the electric driving system 107, and the cooling water cooled at the radiator and the cooling water, removing the heat from the electric driving system 107, after being cooled at the radiator are mixed and supplied to the fuel cell. As a result, circulation of cooling water necessary for cooling both the electric driving system 107 required for relatively retaining at a low temperature and the fuel cell 111 required for retaining at high temperature relatively can be carried out using a single pump 110.