A high sensitive solid-state imaging apparatus which corresponds to an optical system has a short focal length (an optical system having a large incident angle .theta.). Each pixel (2.8 mm square in size) includes a distributed refractive index lens, a color filter for green, Al wirings, a signal transmitting unit, a planarized layer, a light-receiving element (Si photodiode), and an Si substrate. The concentric circle structure of the distributed index lens is made of four types of materials having different refractive indexes such as TiO.sub.2 (n=2.53), SiN (n=2.53), SiO.sub.2 (n=2.53), and air (n=1.0). In the concentric structure, a radial difference of outer peripheries of adjacent circular light-transmitting films is 100 nm. Furthermore, the film thickness is 0.4 .nu.m.