An image sensor comprises: a pixel unit array; a driving unit; a second holding block; a first output amplifier; and a second output amplifier, each column of the pixel unit array including a plurality of first pixel units and a plurality of second pixel units, wherein the driving unit drives the pixel unit array to parallel-perform, on each column of the pixel unit array, an operation to transfer signals from the first pixel units to the first holding block via the first vertical output line, and an operation to transfer signals from the second pixel units to the second holding block via the second vertical output line.