A touch screen device includes a panel body having electrodes arranged in a grid pattern; a sensitivity calculator configured to calculate a sensitivity for each electrode intersection based on an amount of change in a signal output from the electrodes in response to a touch operation; a touch position detector configured to detect the touch position based on the sensitivity obtained by the sensitivity calculator; and a pointing device determiner configured to correct the sensitivity obtained by the sensitivity calculator, based on the touch position obtained by the touch position detector, and to determine whether a pointing device performing the touch operation is a pen or a finger, based on the corrected sensitivity.