PURPOSE: To facilitate pointing when a small sized digitizer inputs a coordinate to a large sized display by moving a corresponding surface to the desired position of a display surface by means of the designation of a pen on the digitizer and displaying a desired dot in the moved corresponding surface.

CONSTITUTION: The surface of the digitizer 10 is caused to correspond to a part 14a of the surface of the display 14, one to one, and the surface 14a corresponding to the digitizer can be moved on the display by an operation on the digitizer. The number of the dots of the digitizer 10 is st to be the same number at the dots of the corresponding surface 14a or more. The corresponding surface 14a on the display is moved by designating the periphery of the surface of the digitizer as specified dots. Thus, the display of high resolution can easily be pointed by the small sized digitizer.