To prevent damage due to a side brush during car wash, irrespective of the shape of a side-view mirror.

When the side brush 4 reaches the position of the side-view mirror by a relative movement of an automobile and a car wash machine body, the side-view mirror is brush washed by rotating the side brush 4 in the direction in which the side-view mirror DM is folded. When the side brush 4 is inclined back and forth at a predetermined value or more during the wash, a catch against the side-view mirror is detected, and the rotation direction of the brush 4 is reversed to release the catch of the side brush 4.