PURPOSE: To reduce the grinding time of a cam by cutting a cam material by means of the oscillation of an oscillating table with respect to a grinding wheel which is previously positioned on an cutting advancing end and, after that, bringing a master cam into contact with a follower roller.

CONSTITUTION: As a starting switch is pressed, a motor 19 is rotated at a low speed and a cam material W supported in the center by a main spindle 33 is rotated at a low speed. After the rotation of the main spindle 33 is started, an oscillating table 14 is oscillated and the cam material W is advanced toward the grinding wheel 3 positioned on a cutting advancing end, to give a rough grinding cutting to the cam material W. When the cam material W is cut up to the rough grinding cutting advancing end, a master cam is brought into contact with a follower roller and, as a result, the oscillating table 14 is oscillated in accordance with the profile of the master cam, to give a creating movement for grinding the cam material W into a required shape to the part between the grinding wheel 3 and the cam material W.