The present invention enables to easily perform a graphic processing even when a touch panel is used. When a resistance film unit is pressed with a pen or a finger, output voltages associated with the X coordinate and the Y coordinate position are changed and these output voltages are transmitted as the X coordinate data and the Y coordinate data to a touch panel driver. According to the output from the resistance film unit, the touch panel driver generates an event for supply to a GUI handler. The touch panel driver includes a two-point specification detector which detects two point specifications and causes to calculate coordinates of the two points. The GUI handler generates a message corresponding to the GUI according to the event and supplies the message to an application. The GUI handler includes a processing mode modification block which differently interprets the event when a single point is specified and when two points are specified, thereby modifying the graphic processing mode.