According to an aspect, a detection device includes: a substrate; a plurality of photodiodes arranged on the substrate; a protective film that covers the photodiodes; a plurality of lenses provided so as to overlap the respective photodiodes; a first light-blocking layer that is provided between the photodiodes and the lenses and is provided with first openings in regions overlapping the respective photodiodes; and a second light-blocking layer that is provided between the first light-blocking layer and the lenses and is provided with second openings in regions overlapping the respective photodiodes and the respective first openings. The first light-blocking layer is provided with slits in regions overlapping gaps between the photodiodes adjacent to each other, and the second light-blocking layer is provided so as to be continuous across the photodiodes adjacent to each other and is provided so as to overlap the slits.