To polish a polished surface of a work piece uniformly with high accuracy by making a polish abutting part with the polished surface of the work piece a straight line shape, and efficiently feeding polishing slurry thereto.

Let a conical polishing pad 5 mounted to a polishing head 2 abut against the polished surface of a substrate W relatively large in diameter so as to allow both the polish abutting surfaces C of them to be a straight line shape, and the polishing head 2 and the substrate W are rotated around their respective axial cores while polishing slurry is being fed to the polish abutting surfaces C, so that chemical and mechanical polishing is thereby ferpormed. When the ratio of revolution speed between the polishing head 2 and the substrate W is set as Rw/Rp, polishing relative speed between them can thereby be made constant over the whole of the abutting surfaces C, the polished surface can thereby be polished uniformly with high accuracy.