A solid-state image pickup device comprising a semiconductor substrate which comprises a substrate body containing P-type impurities and a first N-type semiconductor layer containing N-type impurities, the first N-type semiconductor layer being provided on the substrate body, and including a first P-type semiconductor layer which contains p-type impurities, and which is located on the substrate body, a plurality of optical/electrical conversion portions formed of second N-type semiconductor layers which are provided independently of each other in respective positions in a surface portion of the first N-type semiconductor layer, and a plurality of second P-type semiconductor layers which are formed to surround the optical/electrical conversion portions, which are provided along element isolation regions provided in respective positions in the surface portion of the first N-type semiconductor layer, and which continuously extend from the surface portion of the first N-type semiconductor layer to a surface portion of the first P-type semiconductor layer.