To provide a method for manufacturing an optical element, which improves the surface precision of the optical surface as well as reducing the birefringence at a low cost. A method for manufacturing an optical element 1090A having optical surfaces 1091 and 1092 and a non-optical surface 1093A that is adjacent to the optical surface 1092 via a ridge by injection molding includes forming the non-optical surface 1093A with a mold surface. The mold surface includes a sink forming area 1095 as a first area having a first surface roughness, and a high transfer area 1094 as a second area having a second surface roughness different from the first surface roughness. The second area is located outside the first area.