Abstract: A ball valve comprises a main body having a chamber, inlet and outlet pipes and an extension tube, the chamber having a hollow interior, the extension tube being connected to the hollow interior of the chamber and the inlet and outlet pipes being connected to the hollow interior of the chamber, a switching member having a ball and a rotary shaft, the ball having a channel formed therein correspondingly to the inlet and outlet pipes and the rotary shaft being connected to the ball, and a sealing member having a channel securing hole corresponding to the channel of the ball, the sealing member being formed of elastic material in a cylindrical shape for containing the ball therein.