Disclosed herein is a method of polishing a workpiece having a plurality of resistance elements by operating a plurality of bend mechanisms to push/pull the workpiece with respect to a polishing surface. This method includes the steps of measuring a shape of the workpiece, calculating an operational amount of each bend mechanism according to the shape measured, pressing the workpiece on the polishing surface with the bend mechanisms according to the operational amount calculated, and updating the operational amount according to a working amount of the workpiece. According to this method, magnetic heads included in the workpiece can be stably polished.