The present disclosure relates to a semiconductor device, a solid state imaging element, and an electronic apparatus in which the adverse effect due to hot carrier luminescence can be suppressed. In them, an element formation unit in which a plurality of elements are formed and an interconnection unit in which interconnections connecting elements are formed are stacked. A structure object formed between a light receiving element that receives light and performs photoelectric conversion and an active element that forms a peripheral circuit placed around the light receiving element in such a manner that the gap in the thickness direction of the element formation unit is not more than a prescribed spacing and formed of a material that inhibits the propagation of light is placed in the element formation unit. The present technology can be applied to a back-side illumination solid state imaging element, for example.