In order to discharge air cleaned free from evaporated fuel vapor in a canister installed under the front seat floor, have none of the air coming inside a passenger room and inhibit water, dirt and dust from being absorbed in a drain pipe in a canister, the following drain pipe in a canister is invented. The drain pipe in canister is connected with a canister body installed under a front seat floor of a vehicle. The drain pipe in the canister comprises a first part extending from the canister body up to an upper portion of an engine room disposed on a front side of a passenger room, and a second part extending from the first part to a portion under a floor of the passenger room.