According to an embodiment, a semiconductor device includes a silicon substrate, a photoelectric conversion layer, a termination layer, and an electrode layer. In the silicon substrate, first semiconductor regions and second semiconductor regions are alternately arranged along a first surface on a light incident side of the silicon substrate. The first semiconductor regions are doped with impurities of first concentration and have a conductivity of either one of p-type and n-type. The second semiconductor regions are doped with impurities of a second concentration lower than the first concentration and have a conductivity of the other type. The photoelectric conversion layer is disposed on a first surface side of the silicon substrate. The termination layer is disposed between the silicon substrate and the photoelectric conversion layer, in contact with the first surface, and to terminate dangling bonds of the silicon substrate. The electrode layer is provided on the light incident side.