To prevent cutting fluid from being frozen even in a cold district.

When a workpiece is cut by cutting tools provided with a tool housing, the cutting fluid is injected to a cutting line of the workpiece. A start time for starting circulation of the cutting fluid is switched between a cold mode and a normal mode by a select switch 75. When the select switch is turned ON, start of a cutting fluid driving device 65 is started and the cutting fluid is supplied by injection from an injection nozzle to the cutting line when a power supply SW 69 of a cutting machine is turned ON, and the cutting fluid injected is recovered to circulate again through the injection nozzle. The cutting fluid is thereby prevented from being frozen and, since warming up of the cutting fluid is not required before cutting dead time is reduced. When the select switch is turned OFF, the cutting fluid driving device 65 is not started even when the power supply SW 69 is turned ON, and a cutting start SW 71 for normal workpiece cutting is turned ON or a cleaning SW 73 is turned ON at the time of cleaning the cutting fluid, and the start of the cutting fluid driving device 65 is started.