PURPOSE: To perform engraving of a negative on material to be machined by using an engraved pattern of a positive and to improve machining accuracy.

CONSTITUTION: The material 20 to be machined is positioned and fixed on the position separated by the distance M in the radial direction from the center of rotation on a first supporting table 42. A body 14 to be scanned on which the engraved pattern of the positive having dimensions enlarging by two times a pattern engraved on the material 20 to be machined is drawn is positioned and fixed on the position separated by the distance 2M in the radial direction from the center of rotation on a second supporting table 44. The first supporting table 42 and the second supporting table 44 are rotated in the opposite direction mutually. A feed table 32 is moved in the Y direction by a specified pitch every time the tables 42 and 44 make one revolution. At this time, a detection head 16 is moved in the opposite direction to the table 32. Consequently, the pattern having dimensions reducing the engraved pattern drawn on the body 14 to be scanned to 1/2 is engraved on the material 20 to be machined.