To provide a compact ball valve which can obtain the handle lock mechanism at the entire close time by a simple structure and reduce the number of parts and cost as well as an assembly hour.

In a ball valve opened/closed by turning a valve body 7 by a lever handle 11 inserted in the projected part of a stem 6, the stem 6 is inserted from the inside to the stem through hole 5 of a body 2, a flange 6b provided on the lower outer periphery of the stem 6 is engaged with the lower side of the stem through hole 5, a spring 10 is supported to the stem 6 upper than the lever handle 11 compressigly so as to stop the coming off and stoppers for regulating the movable area of the lever handle 11 and a groove in which the lever handle 11 is inserted unmovably at the close position of the valve body 7 are provided on the upper surface of the body 2 and the ascending energizing of the stem 6 and descending energizing of the lever handle 11 are carried out by the spring 10 and the lever handle 11 of the close position is held in the groove 2e by the spring 10.