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

A valve chest 3 having an inlet 4 and an outlet 5 opened in its lower part and in its upper part respectively is formed by a casing comprising a body 1 and a lid 2. A valve seat 6 is formed between the valve chest 3 and the outlet 5. The valve chest 3 is provided thereinside with an outer float receiver 10 including a flow passage 16 in an area with the inside wall of the valve chest 3, having an almost cylindrical shape with a bottom and containing a through hole 11 in the bottom. The outer float receiver 10 is provided thereinside with an inner float receiver 15 including a flow passage 17 in an area with the inside wall of the outer float receiver 10, having an almost cylindrical shape with a bottom and containing a plurality of microscopic holes 14 in the bottom. Inside the inner float receiver 15, a float 12 is arranged in a free state.