To surely discharge chips generated in cutting and dropping in a dust collecting duct to the outside of the dust collecting duct.

The chips generated from a workpiece cut by a circular saw 21 pass through a housing 22 to drop in the dust collecting duct 30. The dropped chips are discharged from the dust collecting duct 30 to a suction duct 40 by means of a flow of air generated by suction force of the suction duct 40, while being carried to the suction duct 40 side by thrust of an axial direction generated accompanying rotation of a screw 33. The chips are discharged by using not only the suction force of air but also a carrying mechanism by the screw 33, and thereby discharging performance of the chips is excellent.