To provide an exhaust valve which can close a valve after the completion of exhaust even if pressure on an inlet side is high.

A valve chest 3 is formed of a casing comprising a body 1 and a lid 2 in which an inlet 4 is opened on a lower part and an outlet 5 on an upper part. A valve seat 6 is formed between the valve chest 3 and the outlet 5. The body 1 has a plurality of ribs 9 projecting inward on the inner wall of the valve chest 3, and a float receiver 10 in almost the cylindrical shape with a bottom having a male-screw shaped position adjusting member 13 integrally projecting at a lower part from the bottom is arranged inside the rib 9. The bottom of the float receiver 10 has a diversion member 11. The diversion member 11 has a large number of fine holes for communication between the inside and outside. A spherical float 12 is arranged in a free state in the float receiver 10. The body 1 integrally has a mounting member 18 on the inner wall of the inlet 4 through a plurality of ribs 17. The position adjusting member 13 of the float receiver 10 is screwed to the mounting member 18 for connection.