To provide a ball valve which prevents noise generated by a passage for a fluid which passes through a ball in an intermediate open position of the valve.

The ball valve 10 for controlling a rate of flow has a ball 14 which is capable of rotating from a full open position of the valve, which is a positional limit of the valve, to a fully closed position of the valve, which is another positional limit of the valve and vice versa, to provide a passage 16 to the valve. The Passage 16, which is provided with a baffle 17 with a hole therein, allows the fluid to pass through the valve being set in the intermediate position between at least both positional limits above. The baffle 17 with a hole comprises two sheets of metallic plates with a hole between which a layer, which permits the fluid to penetrate, is arranged. In particular, the layer is conveniently formed from a disorderly arranged filament such as steel wool.