PURPOSE: To specify coordinates and sizes as desired by a user at the time of reading parts.

CONSTITUTION: Corresponding to a registration operation from an input device 12, a CPU 10 registers the graphic data of a desired graphic prepared and stored in a graphic memory 14 in a parts memory 16 along with starting point and ending point positions. At the time of preparing the graphic, when the registered graphic data are specified along with the starting point and ending point positions where read is desired by the input device 12, the CPU 10 decides a magnification factor based on the comparison of the specified positions of the two points and the registered positions of the two points of the graphic in the parts memory 16, magnifies the graphic data corresponding to the magnification factor and adds them at the position on the graphic memory 14 corresponding to the specified position.