A fuel cutoff valve has a casing main body, a first float having a smaller specific gravity than a fuel, a second float having a greater specific gravity than the fuel, and a spring. The first float has a float main body and a buoyancy body of a foamed resin. The first float's specific gravity therefore is smaller than the fuel's specific gravity. The first float rises by buoyancy to close a first connection conduit, when a liquid level in a fuel tank exceeds a first liquid level. The second float rises by buoyancy and pressing of the spring to close a second connection conduit, when the liquid level exceeds a second liquid level, higher than the first liquid level. The second float lowers to open the second connection conduit, when the liquid level becomes lower than the second liquid level but is still higher than the first liquid level.