An imaging device including a semiconductor substrate including a first surface that receives light from outside, and a second surface opposite to the first surface; a first transistor located on the second surface; and a photoelectric converter that faces the second surface and that receives light transmitted through the semiconductor substrate. The semiconductor substrate is a silicon substrate or a silicon compound substrate, and the photoelectric converter includes a first electrode electrically connected to the first transistor, a second electrode, and a photoelectric conversion layer that is located between the first electrode and the second electrode and that contains a material which absorbs light having a first wavelength longer than or equal to 1.1 μm, and the material has a quantum nanostructure.