To provide a fuel shut-off valve 10 hardly causing a rise in a fuel liquid level when a vehicle is oscillated, assuring air flow between a fuel tank FT and the outside, and preventing a fuel from flowing out to the outside.

This fuel shut-off valve 10 includes a casing 20 having a first valve chamber 21S, a second valve chamber 22S arranged above the first valve chamber 21S, a first connection passage 23a, and a second connection passage 28b; a first float mechanism 40; and a second float mechanism 60. An air hole 22a is formed at the upper part of the casing 20. The air hole 22a is formed in a passage area increasing the pressure inside the tank up to a pressure value stopping oil feeding in the valve closing state of the first float mechanism 40. The second valve chamber 22S is configured to close the second connection passage 28b by raising the second float mechanism 60 when the fuel flowing in the second valve chamber 22S through the air hole 22a exceeds a prescribed liquid level in the valve closing state of the first float mechanism 40.