PURPOSE: To prevent chips from scattering, preventing thereby the environment from being harmed and preventing a workpiece from being damaged by providing a running groove for a circular saw in the longitudinal direction of a press plate and a cavity communicating with said groove, and connecting a vacuum means provided with a suction port which is opposed to the surface of a placing ruler board to the lower end of said cavity.

CONSTITUTION: When a workpiece W is secured to a work table 3 by means of a press plate 40 and a circular saw 26 is caused to run, with the saw protruding from a slit 6 which allows the saw to run therethrough, the workpiece W is cut by the saw 26. Since the saw 26 cuts the workpiece W by up-cut method, with its ends of saw blade protruding from the surface of the workpiece and facing a running groove 47, most of chips are discharged into a collection cover 32 and discharged to a vacuum means from a suction port 32a, while part of the chips get into a cavity 48 of the plate 40; however, they fall onto a receiving surface 10a of an auxiliary ruler board 10 and are discharged to the vacuum means through a suction port 49. In this manner, the chips are not scattered by the turbulence of air flow caused by the saw during the cutting operation.