PURPOSE: To make any sludge or foreign matter sticking to a working part at the first surface side of a work and a lens supporting part of a working chuck at the second surface side eliminable by installing an eliminator for the foreign matter stuck to the work and/or another eliminator for the foreign matter stuck to a work supporting part of the chuck.

CONSTITUTION: In this device, there are provided a work spindle 29 with a work holding chuck 30 at the tip, a CG wheel spindle 37 for machining a work surface, a wheel spindle 35 for machining a work outer diameter, a work conveyor 44, a device 25 for turning a workpiece upside down and vice versa, and a controller controlling these spindles 29, 37, 35 and devices 44, 25. At this time, there are provided an eliminator 39 for removing any foreign matter stuck to the work 32 and/or another eliminator for removing the foreign matter stuck to a work support part 33 of the chuck 30 as well as a controller for the eliminator 39.