A semiconductor light receiving element of back-illuminated type comprises a light absorbing portion formed in the vicinity of the main surface of the semiconductor substrate transparent to the incident light, and a first convex lens portion larger than the light absorbing portion and having a radius of curvature R1 formed on a back surface of the semiconductor substrate, a second convex lens portion smaller than the light absorbing portion and having a radius of curvature R2 smaller than the radius of curvature R1; the second convex lens portion formed on the first convex lens portion and having a focal point between the second convex lens portion and the light absorbing portion; light incident on the second convex lens portion is diffused from the focal point toward the light absorbing portion.