PURPOSE: To reduce the sliding load of a brush, and to prevent the breakdown of a pattern on the surface of a wafer by sliding a brush member on the surface of the semiconductor wafer, to which water is injected, which is supplied with a surface active agent and which is turned.

CONSTITUTION: The load of a brush 8 is adjusted by a weight 9 while water is injected onto the surface of a semiconductor wafer 1 attracted to a chuck drive section 2 and rotated around a shaft vertical to the surface of the section 2 through a pure water nozzle 10, and the brush 8 is lowered. When water injection is interrupted and a surface active agent is dropped onto the surface of the wafer 1 from a surface active agent nozzle 11, the suction force of foreign matters on the surface of the wafer 1 is weakened, and forsign matters are removed by the brush 8. The sliding load of the brush is reduced by using the surface active agent, and the semiconductor wafer is washed while the breakdown of a pattern on the surface of the wafer is prevented.