A touchscreen apparatus may include: a panel unit including a plurality of first electrodes and a plurality of second electrodes intersecting with the plurality of first electrodes, and a calculating unit obtaining a plurality of pieces of digital data generated from capacitance of node capacitors formed in intersections between the plurality of first electrodes and the plurality of second electrodes. The calculating unit calculates a noise reference level of a current frame using a plurality of pieces of digital data of the current frame and a plurality of pieces of digital data of a previous frame.