PURPOSE: To permit the operator of a CAD device to grasp on which hierarchy in the command system of a whole CAD device a command which is selected at present, is positioned on operating the CAD device on a real time basis.

CONSTITUTION: The CAD device having a keyboard 4 being a means inputting a character, a coordinate and an angle, etc., a pointing device being a means which directly selects the coordinate and an element, a display device 6 being a means displaying the character and the coordinate, which are inputted from the keyboard 4 and the pointing device 5, a display memory 3, a main memory 1 and a central processing unit 2 controlling them are used, and the commands using the CAD device are systematized from a first hierarchy in the order of the hierarchy so as to display them on a display device 6. Thus, the whole positions of the commands in the command system can visually be seen.