A solid-state imaging device 1 according to an embodiment of the invention includes: pixel units P(x, y) each of which includes a photoelectric conversion element and an amplifying unit for a pixel unit and which are two-dimensionally arranged; at least one row of optical black units Pob(x, y) each of which includes a photoelectric conversion element, an amplifying unit for a pixel unit, and a light shielding film that covers the photoelectric conversion element, the photoelectric conversion element and the amplifying unit for a pixel unit being the same as those of the pixel unit P(x, y); and at least one row of optical gray units Pog(x, y) each of which includes an amplifying unit for a pixel unit which is the same as that of the pixel unit and to which a reference voltage is input. The value of the reference voltage is less than the value of the output signal from the photoelectric conversion element in a saturated state.