PURPOSE: To easily produce NC data of a work object having a similar shape by storing only a specified key code, displaying it on a display means, and performing editing processing.

CONSTITUTION: Among key code data of inputted input keys, only key code data in a specified range is stored in a key code memory 8. When NC data to work a work object having a similar shape is produced, this specified key code data is displayed on a CRT 4 being a display means. An operator changes only a changing place by performing input key pressing operation by referring to this displayed key code data, and performs editing processing. Next, this edited key code data is inputted instead of an answer by input, and an NC data is produced by performing automatic programming processing according to this edited key code data.