To grind burrs occurring on a workpiece during metal cutting or deformation processing by making rotating grinding wheels contact the burrs at best angles from the above and below, and then to remove secondary burrs resulting from the burr grinding by a rotating grinding wheel.

A workpiece traveling guide 70 is provided laterally and in parallel to a belt conveyor 20. At around an intermediate position of a traveling direction of the belt conveyor 20, three notches are formed in the workpiece traveling guide 70 and a first rotating grinding wheel 40, a second rotating grinding wheel 50, and a rotating grinding wheel 60 are disposed in order in the notches. When a workpiece 30 is loaded on the belt conveyor 20 and the belt conveyor 20 starts traveling while an edge part 31 of the workpiece 30 is pressed against the workpiece traveling guide 70, the burrs 32 of the end part 31 of the workpiece 30 are successively brought in contact with the first rotating grinding wheel 40, the second rotating grinding wheel 50, and the rotating grinding wheel 60. Thus, the burrs 32 are ground, polished, and removed.