A method for planarizing a workpiece includes bringing a surface of the workpiece and a surface of a pad having a catalyst layer at least on the surface thereof into contact with or proximal to each other, rotating a first one of the workpiece and the pad in a plane of the surface of the first one around a central axis that intersects the surface of the first one while supplying a liquid that supports a catalytic reaction between the surface of the workpiece and the catalyst layer on the surface of the pad, and simultaneously reciprocally moving a second one of the workpiece and the pad in a direction parallel to the surface of the second one by at least an amount that makes possible planarization of the surface of the workpiece based on the catalytic reaction.