PURPOSE: To prevent the ratio of air to fuel from decreasing, by stopping or reducing purge when the temperature of cooling water of an engine is high.

CONSTITUTION: A part of BVSV4 is dipped in the water of an engine. A VSV5 is a solenoid valve electrically coupled to an electric wire 8 at the side of an electric fan 7 for cooling the water of the engine. When a water temperature switch 9 is closed as a result of the rise in the temperature of the water, a relay 10 acts to supply an electrical current from a power source 11 to the fan 7 and the VSV5 so that an electromagnetic mechanism closes a main passage 12a and opens an auxiliary passage 12b provided with an orifice 6. As a result, the purge from a canister 2 is reduced by the orifice 6 so that excessive purge is avoided.