A method for fabricating a semiconductor device includes grindstone surface activation treatment by means of a brush or ultrasonic wave carried out when a concave/convex pattern of a semiconductor wafer is planarized by polishing a semiconductor wafer held by a wafer holder by using a grindstone constituted of abrasive grains and material for holding the abrasive grains onto which the semiconductor wafer is pressed with relative motion. The semiconductor wafer is processed with high removal rate and the polishing thickness is controlled accurately.