To provide an optical element which has excellent light resistance to exposing light of short wavelength and is provided with a reflection preventing film and to provide an exposure apparatus having the optical element.

The optical element comprises: a substrate through which light rays having a central wavelength in the wavelength of 150 nm to 250 nm are passed; and the reflection preventing film which is formed on the substrate and is composed of n-layers (wherein n is an integer of ≥3). The optical element is characterized in that the (n-2)th layer counted from the substrate is composed of a material having a large refractive index, the (n-1)th layer is composed of an amorphous material including AlF3, the n-th layer is composed of a material having a small refractive index, and the material having a large refractive index and the material having a small refractive index include a crystalline material.