To input absolute coordinates without using any dedicated device driver and eliminates the need for calibration operation accompanying a change in resolution by sending out relative coordinate data corresponding to the difference between absolute coordinate data on cursor coordinates and a target position to an operating system until the difference is removed, and moving a cursor.

An interface device 5 regards absolute coordinate data sent out of the screen position indicating device 1 as absolute coordinate data on the target position and absolute coordinate data sent out of the screen position indicating device 1 right before the absolute coordinate data on the target position as absolute coordinate data on an original position, and calculates the difference between the absolute coordinate data on the target position and the absolute coordinate data on the original position and sends relative coordinate data corresponding to the difference to the operating system 3 through a device driver 4 for pointing, thereby moving the cursor on the display.