1. A solid-state image pickup device comprising: a plurality of pixels each including: a photoelectric conversion section that generates an electric charge in accordance with incident light; and a junction field-effect transistor that outputs an image signal in accordance with the electric charge generated by the photoelectric conversion section, wherein the solid-state image pickup device includes a first element isolation region using an insulator and a second element isolation region using a pn junction, the first element isolation region and the second element isolation region being arranged in a region in which the plurality of pixels are arranged, and a channel of the junction field-effect transistor and the second element isolation region is arranged along a line that is parallel to a channel direction of the junction field-effect transistor.