An optical element having an anti-reflection function includes a base having a first main surface and a second main surface; a plurality of structures composed of projections or recesses and arranged on the first main surface at a fine pitch equal to or less than the wavelength of visible light for which the amount of reflection is to be reduced; and a light-absorbing layer that absorbs the light and that is disposed on the second main surface, wherein the structures are arranged so as to form a plurality of rows of tracks on the first main surface and form a hexagonal lattice pattern, a quasi-hexagonal lattice pattern, a tetragonal lattice pattern, or a quasi-tetragonal lattice pattern, and the structures each have an elliptical cone shape or a truncated elliptical cone shape, the major axis direction of which is a direction in which the tracks extend.