According to one embodiment, a display device includes a plurality of gate lines, a plurality of data lines intersecting with the gate lines, a plurality of pixel electrodes provided in areas defined by the gate lines and the data lines, and a sensor drive controller which includes a plurality of common electrodes facing the pixel electrodes and detects a touch by using the common electrodes. The sensor drive controller selects at least one of the common electrodes as a sensor electrode, detects a touch by using the sensor electrode, and inputs, to the other common electrodes, a guard signal for reducing generation of capacitance between the other common electrodes and the sensor electrode.