PURPOSE: To realize a personal computer with good handleability by constituting the computer so that at the time of inputting data and a command to the personal computer, they can be instructed with a pen and a finger even in a system whose screen is large.

CONSTITUTION: When a touch panel 2 is depressed with a digitizer input pen 4, a depressing signal is outputted from a digitizer controller 7, and also, a depressing signal is outputted from a touch panel controller 6, as well. When the depressing signal is outputted, an effective input discriminating means 10 starts its operation, an effective coordinate value is selected from in a coordinate value outputted from the touch panel controller 6 and a coordinate value outputted from the digitizer controller 7, and the selected coordinate value is delivered to a processing means 11. In such a manner, data and a command can be inputted easily irrespective of an input device (pen, etc.).