A solid-state imaging device comprising: a substrate having a first substrate surface side to be irradiated with light and a second substrate surface side opposed to the first substrate surface side; a photoelectric conversion part including a first conductivity type semiconductor layer formed between the first substrate surface side and the second substrate surface side of the substrate, the photoelectric conversion part being configured to perform photoelectric conversion of received light and store charges; a second conductivity type semiconductor layer formed at least on a side portion of the first conductivity type semiconductor layer of the photoelectric conversion part; a transfer transistor (TG1-Tr) for transferring the charges stored in the photoelectric conversion part; a floating diffusion to which the charges are transferred through the transfer transistor (TG1-Tr); a storage transistor (SG1-Tr) connected to the floating diffusion; and a storage capacitance element for storing the charges received from the floating diffusion via the storage transistor (SG1-Tr), wherein the storage capacitance element is formed on the second substrate surface side so as to spatially overlap with at least a part of the photoelectric conversion part in a direction perpendicular to a substrate surface, wherein the photoelectric conversion part includes a second conductivity type semiconductor region formed on a surface of the first conductivity type semiconductor layer on the second substrate surface side, and wherein the storage capacitance element uses, as the first electrode thereof, the second conductivity type semiconductor region formed on the surface on the second substrate surface side. a substrate having a first substrate surface side to be irradiated with light and a second substrate surface side opposed to the first substrate surface side; a photoelectric conversion part including a first conductivity type semiconductor layer formed between the first substrate surface side and the second substrate surface side of the substrate, the photoelectric conversion part being configured to perform photoelectric conversion of received light and store charges; a second conductivity type semiconductor layer formed at least on a side portion of the first conductivity type semiconductor layer of the photoelectric conversion part; a transfer transistor (TG1-Tr) for transferring the charges stored in the photoelectric conversion part; a floating diffusion to which the charges are transferred through the transfer transistor (TG1-Tr); a storage transistor (SG1-Tr) connected to the floating diffusion; and a storage capacitance element for storing the charges received from the floating diffusion via the storage transistor (SG1-Tr), wherein the storage capacitance element is formed on the second substrate surface side so as to spatially overlap with at least a part of the photoelectric conversion part in a direction perpendicular to a substrate surface, wherein the photoelectric conversion part includes a second conductivity type semiconductor region formed on a surface of the first conductivity type semiconductor layer on the second substrate surface side, and wherein the storage capacitance element uses, as the first electrode thereof, the second conductivity type semiconductor region formed on the surface on the second substrate surface side.