FUEL SUPPLY DEVICE

A fuel feed system which causes liquid fuel to evaporate so as to feed gaseous fuel, provided with an evaporator which includes a heater which heats the liquid fuel to vaporize it and an electric heater which adjusts the temperature of the heater. The heater has a heat conduction surface which supplies heat to the liquid fuel. A difference between the temperature of the heat conduction surface of the heater and the boiling point of the fuel at the evaporator is used as the basis to change the temperature of the heater and adjust the heat flux at the heat conduction surface.