To efficiently restrain temperature decrease of a pressure controller caused in accordance with pressure reduction of hydrogen.

Hydrogen supplied from a hydrogen tank 111 to a fuel cell stack 121 is decompressed from 350 atm. to 2 atm. or so by the pressure controller 112. At this time, the temperature of the pressure controller 112 is theoretically decreased to -205°C by adiabatic expansion of hydrogen. On that account, the pressure controller 112 is arranged at a location where the controller 112 can receive the heat radiated from a radiator 113. When the temperature of cooling liquid flowing through the radiator 113 is low, to prevent excessive cooling of the fuel cell stack 121, outside air is introduced from a duct 132 in a state that a radiator flap 115 is closed, and temperature decrease in the pressure controller 112 can be restrained by the outside air.