A solid-state imaging device includes: a p-type semiconductor substrate; an n-type first semiconductor layer located above the semiconductor substrate and forming a junction with the semiconductor substrate in the first area; and an n-type second semiconductor layer located between the semiconductor substrate and the first semiconductor layer in the second area outward of the first area and having an impurity concentration lower than an impurity concentration of the first semiconductor layer. The semiconductor substrate and the first semiconductor layer form APD1, and the second semiconductor layer extends to a level below an interface between the semiconductor substrate and the first semiconductor layer in a thickness direction of the semiconductor substrate.