An input device or an input/output device that is suitable for increasing in size is provided. An input device or an input/output device that can be driven at high frequencies is provided. An input device includes a plurality of row wirings and a plurality of column wirings. To each of the plurality of row wirings, periodic rectangular waves are applied. When attention is paid to one row wiring Xi (i is greater than or equal to 1 and less than or equal to m−1), a signal that has a phase opposite to that of a signal applied to the row wiring Xi and that is delayed for a given period is applied to a row wiring Xi+1, which is the row wiring next to the row wiring Xi. The width of each of the rectangular waves applied to the row wirings corresponds to a frame period.