Provided are imaging apparatus and radiation detecting apparatus with high sensitivity. An imaging apparatus has a photoelectric conversion layer 16 for converting incident light into charge, on an insulating substrate, an electrode layer 17 formed on the photoelectric conversion layer 16, and a protective layer 37 formed on the electrode layer 17, and satisfies relations of na−nb≦1.5 and nb−nc≦1.5 where na is a refractive index of the photoelectric conversion layer 16, nb a refractive index of the electrode layer 17, and nc a refractive index of the protective layer 37.