To provide a fuel shut-off valve 10 reducing contact noises between a float and a guide member in the inner periphery of a case, caused by flow-in/out of a fuel upon oscillation or braking of a vehicle.

This fuel shut-off valve 10 includes a case body 30 forming a valve chamber 30S, and a float mechanism 50 elevatably stored in the valve chamber 30S. The case body 30 includes the guide member 36 protruded from a partition wall 32 in the valve chamber 30S, which is apart from a sidewall 31 by an annular recess 37.