POLISHING MACHINE

PROBLEM TO BE SOLVED: To enable an operator to substantially ignore a temperature rise in a working surface of a surface plate even after the start of operation by providing a temperature controller at a speed reducer installed at a lower part of the surface plate. SOLUTION: Upper and lower surface plates 1, 2, a sun gear 4 and an internal gear 5 constituting a polishing machine is driven by a drive motor 8 and a speed reducer 9 installed in a device body box 7. A cooling jacket 10 is arranged to spirally surround the reducer 9. Refregerant for cooling is controlled in its temperature at a preliminarily set temperature by a refregerant temperature controller 11 and circulated in the jacket 10 by a circulation pump to control temperature increase in the reducer 9. Accordingly, the temperature increase in the reducer 9 is restrained, and though raised temperature is transmitted to the lower surface plate 2 the temperature increase is prevented, and further the whole system is maintained in its temperature at the temperature around the room temperature.