To provide a method for manufacturing an optical element which can reduce the incidence of "sink marks" generated during molding an ultraviolet-curable resin.

In this method, an ultraviolet-curable resin 3 is injected into between a mold 1 with a flat surface and glass 2 as an optical element with a concentric circle-like relief pattern formed on the surface, using a dispenser or the like and pressed and cured by irradiating the resin 3 with ultraviolet light through a filter 4. Finally the optical element with a circular diffraction grating formed in the interface between the ultraviolet-curable resin 3 and the glass 2, is completed by releasing the cured ultraviolet-curable resin 3 and the glass 2 from the mold 1. The gradient direction of the relief pattern, on the surface of the glass 2, which becomes a pattern of the ultraviolet-curable resin 3, proceeds to the center of the concentric circle from its peripheral edge. Therefore, in this case, it is so designed that the luminosity of the ultraviolet light, which iradiates each part of the ultraviolet-curable resin 3, may be as shown in (b) of Fig. to the radius by increasing the transmittance of the filter 4 in its center and decreasing it at its peripheral edge.