To provide an optical element having such a structure that the transmittance continuously and gradually increases from a center portion to a peripheral portion, in which a regular reflectance is low in a region where the transmittance gradually decreases from an opening of the center portion to a peripheral portion.

The optical element has such a structure that a light-absorbing material layer is formed on a transparent substrate and the transmittance for light decreases from a center portion to a peripheral portion. The light-absorbing material layer is configured to be thinnest in a center portion 21a and to have a film thickness gradient region 21a in a periphery of the center portion 21a, where the film thickness gradually increases with an increase in the distance from the center portion. The surface roughness in the film thickness gradient region 21b is 15 nm or more.