An optical member comprising (1, 2, 3, 4, 5): a transparent substrate; and an anti-reflection film that is formed on a surface of the transparent substrate, wherein the anti-reflection film includes a refractive index gradient structure layer of which a refractive index gradually becomes larger at a position closer to the transparent substrate in a thickness direction, and an interference layer which is disposed between the refractive index gradient structure layer and the transparent substrate in order to prevent light from being reflected by an interference effect, wherein a refractive index of the transparent substrate is different from a refractive index of the refractive index gradient structure layer on a side closest to the transparent substrate, and wherein a refractive index of the interference layer changes in the thickness direction, and has values which are discrete from both refractive indexes of the refractive index gradient structure layer and the transparent substrate at a boundary between the interference layer and the refractive index gradient structure layer and at a boundary between the interference layer and the transparent substrate, and a value thereof on a side close to the refractive index gradient structure layer is different from a value thereof on a side close to the transparent substrate, and wherein in the interference layer, a refractive index at the boundary position between the interference layer and the refractive index gradient structure layer is smaller than a refractive index at the boundary position between the interference layer and the transparent substrate, characterized in that the refractive index of the transparent substrate is smaller than the refractive index of the refractive index gradient structure layer on the side closest to the transparent substrate. a transparent substrate; and an anti-reflection film that is formed on a surface of the transparent substrate, wherein the anti-reflection film includes a refractive index gradient structure layer of which a refractive index gradually becomes larger at a position closer to the transparent substrate in a thickness direction, and an interference layer which is disposed between the refractive index gradient structure layer and the transparent substrate in order to prevent light from being reflected by an interference effect, wherein a refractive index of the transparent substrate is different from a refractive index of the refractive index gradient structure layer on a side closest to the transparent substrate, and wherein a refractive index of the interference layer changes in the thickness direction, and has values which are discrete from both refractive indexes of the refractive index gradient structure layer and the transparent substrate at a boundary between the interference layer and the refractive index gradient structure layer and at a boundary between the interference layer and the transparent substrate, and a value thereof on a side close to the refractive index gradient structure layer is different from a value thereof on a side close to the transparent substrate, and wherein in the interference layer, a refractive index at the boundary position between the interference layer and the refractive index gradient structure layer is smaller than a refractive index at the boundary position between the interference layer and the transparent substrate, characterized in that the refractive index of the transparent substrate is smaller than the refractive index of the refractive index gradient structure layer on the side closest to the transparent substrate.