PURPOSE: To extract an optical signal charge with less dark current component by providing 2 rows of vertical registers to one row of photoelectric conversion section.

CONSTITUTION: A different voltage is applied to two layers of electrodes 8, 9 forming a vertical register 6 to cause a difference to a lower potential to form the potential. Thus, the vertical register 6 forms an optical signal charge to the lower electrode 8 not used for a readout gate and the vertical register 7 forms an optical signal charge to the lower electrode 8 not used for a readout gate. Thus, 2 rows of the vertical registers are provided to one row of photoelectric conversion section to store the optical signal charge only at the lower part of the electrode 8 not used as the readout gate of the optical signal charge stored in the photoelectric conversion section 1 and the optical signal charge with less dark current component is extracted.