An image sensor includes a semiconductor layer, an organic photoelectric conversion portion disposed on an upper surface of the semiconductor layer and that converts a color component of incident light into a corresponding electrical signal, a transistor layer disposed on a lower surface of the semiconductor layer and including a pixel circuit that receives the electrical signal, and penetration wiring that laterally penetrates a side surface of the semiconductor layer between the upper and lower surfaces and that electrically connects the organic photoelectric conversion portion with the pixel circuit to communicate the electrical signal.