A washing machine capable of manipulating a balancer with a simple manipulation, and a balancer thereof, the washing machine including a rotating tub configured to accommodate a laundry while being rotatably disposed on a shaft, at least one mass mounted on the rotating tub so as to move in a circumferential direction of the rotating tub, thereby offsetting an unbalanced load of the rotating tub, at least one wire extending along the circumferential direction of the rotating tub and coupled to the at least one mass, and at least one driving unit coupled to the at least one wire and configured to rotate the at least one mass in the circumferential direction of the rotating tub.