A method of polishing one side of a wafer, which makes it possible to accurately realize the desired wafer edge shape without dependence on the period of use of a polishing cloth, is provided. In the method according to the present invention, a wafer fixed to a head is brought into contact with a polishing cloth provided on a surface of a surface plate, and the head and the surface plate are rotated, thereby polishing one side of the wafer, the method including the steps of measuring a contact angle of the polishing cloth (S1); determining a rotation speed of the head and the surface plate, based on the measured contact angle of the polishing cloth (S4); and polishing the one side of the wafer by rotating the head and the surface plate at the determined rotation speed (S5, S6).