Provided are a window cleaning apparatus including first and second cleaning units which are respectively attached on both surfaces of a window using a magnetic force to move together with each other, and a method for controlling a movement of the window cleaning apparatus. The window cleaning apparatus includes a direction detecting sensor, a control part, a collision sensing part, and an offset setting part. The direction detecting sensor is provided to at least one of the first and second cleaning units to detect a moving direction of the window cleaning apparatus. The control part controls a movement of the window cleaning apparatus, based on the moving direction detected by the direction detecting sensor. The collision sensing part senses a shock to the window cleaning apparatus. The offset setting part sets a direction offset of the direction detecting sensor when the window cleaning apparatus collides with a frame of the window.