To provide an exhaust valve capable of being closed after completion of the exhaust even if the pressure on the inlet port side is high.

A valve chest 3 furnished with an inlet port 4 in the lower part and with an outlet port 5 in the upper part is formed from a casing consisting of a body 1 and lid 2. The body 1 is furnished rigidly with a plurality of ribs 9 protruding inward to the inner wall of the valve chest 3, and a float receptacle 10 in the form approximately of a bottom-equipped cylinder and having a vent 11 at the bottom is fixed to the insides of the ribs 9 using a snap ring. A float 12 in a spherical shape is set in free state in the float receptacle 10. The float receptacle 10 is furnished rigidly with a bulkhead 13 on the inner wall with a plurality of ribs 14 interposed. The bulkhead 13 is positioned below the float 12 and hinders the fluid from going straight from the vent 11 to the float 12.