Washing machine having balancer

Washing machine comprising a spin tub (10) to hold laundry to be washed, and at least one ball balancer (20, 30), the ball balancer (20, 30) comprising a first housing (22) having an open side, first and second walls (22a, 22b) facing each other and a third wall (22c) formed between the first and second walls (22a, 22b), a second housing (23) to cover the open side of the first housing (22), wherein the first and second housing (22, 23) are joined together to form an annular shaped space (20a) within which a plurality of balls (21) is movably disposed , wherein at least one support (24, 34) is provided to the first housing (22) along at least the first wall (22a) thereof, and whereby the spin tub (10) has an annular recess (15), wherein said at least one ball balancer (20, 30) is installed in the annular recess (15) of the spin tub (10) to compensate for a dynamic imbalance.