A detecting device includes a substrate, a plurality of detection electrodes provided on the substrate and arrayed in a first direction parallel to the substrate, a plurality of drive electrodes provided on the substrate and arrayed in a second direction intersecting the first direction, a second selection circuit configured to select a plurality of the detection electrodes based on selection signals, a first selection circuit configured to select a plurality of the drive electrodes, a detector coupled to the selected detection electrodes out of the detection electrodes, and a memory storing therein, as a set of output data, a plurality of detection signals output from the selected detection electrodes via the detector by the first selection circuit scanning the drive electrodes in one period when the second selection circuit selects the detection electrodes.