PURPOSE: To prevent air-fuel mixture from becoming excessively thick even when the temperature of the fuel is high and to maintain an air-fuel ratio at an appropriate value to prevent worsening of exhaust emission, by stopping introduction of a purge air to an adsorptive layer and stopping separation of fuel vapor from the adsorptive layer.

CONSTITUTION: When the temperature of the air in a fuel tank 1 is below a set temperature, purge air is introduced only from a purge air introducing part 11, through the open air releasing port C of a 3-way electromagnetic valve 36, a port A and a hose 34, and the adsorbed vapor fuel is separated from two adsorptive layers 9a and 9b. Meanwhile, when the temperature of the fuel exceeds a set temperature, the purge air introducing part 11 is closed, an auxiliary purge air introducing part 33 is opened, and the purge air is introduced from only the auxiliary purge air introducing part through the open air releasing port C, a port B, and a hose 35, whereby the adsorbed vaporized fuel is separated from only the adsorptive layer 9a but not separated from the adsorptive layer 9b.