adsorption strength of a contact surface of the lower polishing mechanism onto the object application_number US 29767305 A description the workpiece to be polished may preferably comprise glass b c or si or a metal or an alloy of two or more metals selected from the group consisting of fe cr ni cu co al sn mo w ta ti and nb the workpiece may be the one coated with any of these materials it may be preferable that the workpiece has flat surfaces and is a plate such as a circular square or rectangular plate specifically it may include a glass substrate for liquid crystal display a hard disk substrate and a semiconductor wafer the polishing apparatus used in the present invention has upper and lower polishing mechanisms capable of polishing the surfaces of a workpiece from the upper and lower sides the sliding or rotation can polish away defects and irregularities on the surfaces of the workpiece the upper and lower polishing mechanisms may for example have vertically moving shafts to be rotated by a drive motor or the like the rotation mechanisms may be preferably synchronized and optionally have a mechanism capable of changing torque or of reverse rotation the upper and lower mechanisms may be typically rotated in the opposite directions to each other the upper and lower polishing mechanisms may preferably comprise.