PURPOSE: To reduce the cutting resistance and improve the working precision by using a cutter whose rotational diameter is small, and inclining the main spindle where this cutter is mounted to the specified direction to execute the cutting in working the lead part of the cylinder of a video tape recorder.

CONSTITUTION: A work 10 as a rotary body having a lead part 17 is screwed and fixed to a work rotation drive shaft 12 which is integrated with an output shaft 25 of a motor for driving the work. A cutter shaft 14 which is the main spindle is mounted on a cutter spindle 8 to be held on a spindle fixing table, and the targeted lead shape (lead locus) is worked on the lead part 17 by the blade (tool) mounted on the tip part of this cutter shaft 14. The axis of rotation of the cutter shaft 14 is inclined to the direction orthogonal to the axis of rotation of the work rotation drive shaft 12 by the angle 16 (2-10°) on the opposite side to the lead part 17 of the work 10. The cutter whose diameter of rotation is small, i.e., the cutter of 6-10mm in diameter is used as the cutter 15.