PURPOSE: To contrive a shortening in working hours and to reduce the number of polishing devices by a method wherein when a wafer is polished, a coarse polishing is performed by the same polishing device without changing a polisher (a polishing cloth) and the diameters of abrasive grains and subsequently to the coarse polishing, a finishing polishing is performed by the same polishing device.

CONSTITUTION: Abrasive grains suspended with an abrasive liquid are placed on a polisher 2 fixed on a surface plate 1, a wafer 5 is placed thereon, a load 6 larger than that at the time of a finishing polishing is applied on the wafer 5 and a relative velocity 7 is given to the surface plate 1 and the wafer 5 to make to perform a friction motion in the horizontal direction. At the time of a coarse polishing which is performed by this friction motion, the relative velocity to give to the polisher and the wafer is set in 0.1m/s-5m/s and a pressing force to the polisher and the wafer is set to 100-400g/cm2. Then, the finishing polishing is performed using the same polishing device without changing the polisher 2 and the diameters of the abrasive grains 4. The relative velocity to give to the polisher and the wafer at the time of this finishing polishing is set in 20m/s or more and the pressing force to the polisher and the wafer is set in 10-50g/cm2.