PURPOSE: To shorten idling time until a relative change in bite height can be stabilized, and obviate reidling caused by a change in the number of revolutions of a main shaft and readjustment of the bite height.

CONSTITUTION: A refrigerant 65 in a tank 66 is supplied to a main shaft stand 6, and the refrigerant 65 whose temperature is raised after the main shaft stand 6 is cooled is supplied to an X axis table 5 and a circular table 8, and is flowed back to the tank 66 from the tables 5 and 8. Thereby, since the refrigerant is supplied to the main shaft stand and the refrigerant whose temperature is raised after the main shaft stand is cooled is supplied to the tables, The temperature of the tables is raised and is maintained at the same temperature (or constant temperature difference) as the main shaft stand, and relative dislocation between the main shaft stand and the tables can be prevented. Thereby, idling time can be shortened, and adjustment of bite height caused by a change in the number of revolutions of a main shaft can be obviated.