Abstract: The present invention provides equipment for brushing the underside of a semiconductorwafer that is placed on a rotary wafer chuck. The equipment comprises a brush rod, a brush with a channel in it mounted at an end point of the brush rod, a nozzle for spraying water on the underside of the semiconductor wafer, and a driving device connected to the brush rod for driving the brush rod in a reciprocating motion. The wafer chuck rotates the semiconductor wafer and, simultaneously, water drives the blade and the brush to raise and rotate so as to spray water over the underside of the semiconductor wafer. The driving device drives the brush to brush the underside of the semiconductor wafer along a radial direction of the semiconductor wafer.