Suppress deterioration in picture qualities while achieving expansion in a dynamic range.An image sensor readout method that reads out, from an area sensor where a plurality of image pickup elements are arranged in matrix, signal charges that are accumulated in the image pickup elements is constituted as follows. First, plural kinds of exposure time different in length from each other are set, and the exposure time is then individually allocated to each line of the area sensor. Next, the signal charges accumulated in the image pickup elements in the allocated exposure time are read out through a line unit of the area sensor. Then, the read out signal charges are synthesized through a screen unit of the area sensor.