A tank passage is connected at its one end to a fuel tank, which stores fuel. A canister is connected to the other end of the tank passage and adsorbs evaporated fuel generated by evaporation of fuel in the fuel tank. An electric control valve is operable with current supply to control an amount of fluid flowing through the tank passage by varying an open rate of the tank passage. A fill-up detection part detects that the fuel tank is filled up with fuel based on a fuel level in the fuel tank. A control part controls an operation of the electric control valve. The control part controls the electric control valve in the valve closing direction, which decreases the open rate, when the fill-up detection part detects that the fuel tank is filled up with fuel.