The two-dimensional solid state image pickup device shown in FIG. 9 has: a light receiving unit 301 composed of pixels (including light receiving elements such as photodiode, and amplifier circuit) 300; a signal readout unit 200 having line memories CT101 to CT108 (203), first switches M101 to M108 (208), first common signal line 212, second switches M201, M202 (220), and second common signal line