According to one embodiment, an imaging device includes a semiconductor layer, an electrode, first and second insulating films, and a light blocking film. The semiconductor layer has a first surface and a second surface on an opposite side to the first surface, and includes pixels configured to detect light. The electrode is provided on the first surface and is configured to control an output of the pixels. The first insulating film is provided on the second surface. The second insulating film is provided on the first insulating film and has a smaller refractive index in a visible light range than the first insulating film. One end of the light blocking film is located in the second insulating film or at a same level as a surface of the second insulating film. Another end of the light blocking film is located in the semiconductor layer.