There is configured a solid-state image pickup unit including a photoelectric conversion section formed on a light incident side of a substrate; a first charge accumulation section accumulating a signal charge generated by the photoelectric conversion section; a second charge accumulation section formed in a region other than a light-condensing region where incident light is condensed in the substrate on a side opposite to a light incident side and formed to be laminated together with the first charge accumulation section in a depth direction of the substrate; and a floating diffusion section formed in a region other than the light-condensing region in the substrate on the side opposite to the light incident side and converting the signal charge into a voltage.