PURPOSE: To prevent a brush and a car body from being damaged by catching motion, by stopping car washing operation temporarily when the catching motion happens, while restarting the car washing operation after the catching motion is automatically released.

CONSTITUTION: A side brush 3, a top brush 4 and a rocker brush 5 are all provided with each sensor which senses a fact that load of the bristles of each brush is imposed on the reverse direction against the advance of a body 1 or the reverse direction of rotation in these brushes as they are caught by a car body. When this catching happens, first of all, a car washing program is suspended, while catching release operation takes place for a set time long, and then the car washing program is made to operate so as to reopen it from the stopping position.