PURPOSE: To make automatically a cutting operation and to improve working efficiency by driving vertically a cutting tool according to the forward and backward movement of a working table and cutting a product from a runner.

CONSTITUTION: A grinding wheel 18 is positioned and the 2nd driving source is operated to rotate the wheel 18; at the same time, the 3rd driving source 28 is operated to rotate a feed screw 26. The working table 33 is driven and the product 41 in the lowermost stage of a material 38 to be cut is cut from subrunners 40. A lifting table 6 is then raised by the 1st driving source 8 to locate the wheel 18 to the prescribed position. The 2nd product 41 from below is then cut away from the runner 40 when the table 33 is driven backward by the 3rd driving source 28. The wheel 18 is raised by each prescribed size in the above-mentioned manner according to the forward and backward movement of the table 33, then the products 41 formed continuously to the runners 40 on both side faces of the main runner 39 of the material 38 to be cut are automatically cut by the wheel 18.