A detection device includes a sensor unit in which a plurality of detection electrodes is positioned in a detection surface, a selection unit that selects one of the plurality of detection electrodes or a plurality of detection electrodes, an oscillation unit in which an oscillation frequency is determined by a capacitance generated in the one or plurality of detection electrodes selected by the selection unit, a conversion unit that outputs a signal corresponding to the frequency of a signal from the oscillation unit, and a switch unit that performs electrical connection/disconnection between a wiring for connecting the oscillation unit and the selection unit and a constant voltage line.