Disclosed herein is a solid-state image pickup device including: a plurality of unit pixels each having: a charge generating section for generating a charge, a charge storage section for storing the charge generated by the charge generating section, a transfer gate section disposed between the charge generating section and the charge storage section for transferring the charge generated by the charge generating section to the charge storage section, and a pixel signal generating section for generating a pixel signal corresponding to the charge stored in the charge storage section; an unnecessary charge discharging gate section in each the unit pixel, switchable to block a flow of an unnecessary charge that is generated in the charge generating section and does not contribute to image formation, according to height of an electric barrier; and an unnecessary charge drain section disposed on an opposite side of the unnecessary charge discharging gate section from the charge generating section for receiving the unnecessary charge swept out of the charge generating section through the unnecessary charge discharging gate section.