A housing of a fuel vapor leak check module is arranged close to a canister by inserting a canister port into the canister. A distance between the canister and the leak check module is reduced. A centerline of the canister port is approximately parallel to a centerline of an atmospheric vent port. A brushless motor of which axial length is relatively short drives a pump so that the housing is formed stepwise at the side opposite to the canister. A connector is disposed on the housing accommodating the pump to reduce a dead space.