An imaging element included in an imaging device includes a pixel array in which a plurality of unit pixels are arranged in a matrix, each of the unit pixels having a photoelectric conversion unit. The imaging element is able to read out multiple rows of pixel signals in parallel in a unit horizontal synchronous period. The multiple rows of pixel groups are classified into a first pixel group and a second pixel group by a plurality of rows control signals, and are periodically arranged in a vertical direction of the imaging element. The imaging element is able to acquire signals obtained by multiplying different gains by pixel signals of unit pixels of the first pixel group and pixel signals of unit pixels of the second pixel group through setting of a plurality of rows control signals.