A washing apparatus comprising a tub provided inside a cabinet; a drum provided inside the tub so as to be rotatable; a balancer housing installed on the front or rear side of the drum; and a balancing unit that includes a body, a drive motor, and a drive gear, the balancing unit movable in the balancer housing to reduce the eccentricity of the drum, wherein gear teeth are formed along an inner circumferential surface of the balancer housing, and the balancing unit is disposed in the balancer housing such that the drive gear is exposed to the outside of the body of the balancing unit to engage with the gear teeth.