PURPOSE: To simplify the construction of a process for picture drawing and to easily perform a touch input operation by providing a dedicated touchmark display means.

CONSTITUTION: The touchmark display means, a touchmark fixing display means, and a touchcursor display means, are provided. Therefore, when touch- inputting the inside of a registration area set in advance corresponding to a display picture 1 of the screen, a touchmark 3, composed of the outline frame of a prescribed dimension and a center position display part, is displayed by the exclusive display device in the center position of the registration area even when the touchposition is positioned anywhere in the inside of the registration area. When the touchposition based on the touch input is the outside of the registration area, a normal touchcursor 2, which shape is different from the touchmark 3, is displayed corresponding to the input position. Thus, the plotting process by the software of the touchmark 3 is unnecessitated, and the control of the picture plotting process can be simplified.