A display device according to the present inventive concept includes: a display panel comprising a pixel electrode receiving a data voltage and a common electrode receiving a common voltage; and a touch sensor comprising a plurality of driving electrodes and a plurality of sensing electrodes, wherein the touch sensor applies a touch detection signal to the plurality of driving electrode and detects a touch location by receiving a sense signal from the plurality of sensing electrode in an active mode, and determines whether a touch is made by receiving sense signals of the plurality of sensing electrodes, that are fluctuated by a ripple of a common voltage applied to the common electrode according to driving of the display panel in an idle mode.