There is a known solid state imaging device provided with a photoelectric conversion portion having a plurality of photosensitive regions to generate respective charges according to incidence of light, and a potential gradient forming portion having an electroconductive member arranged opposite to the photosensitive regions (e.g., cf. Patent Literature 1). In the solid state imaging device described in Patent Literature 1, the potential gradient forming portion forms a potential gradient becoming higher along a predetermined direction. The charges are moved by this potential gradient, thereby achieving increase of charge readout speed.