Abstract: Within a hood, pressurized cold air is injected from a cold air injection pipe to the spindle and the cutting tool for a machine tool for cooling them and at the same time air is sucked and discharged through a discharge port provided on the hood from the inside of the hood by means of a vacuum pressure produced by a suction device. When air is discharged, a swirl is generated in the hood by discharged air and by deflected air streams passed through a plurality of guide blades provided at the open end of the hood. The cutting chips are floated up by the swirl and discharged together with air through the discharge port.