An exposure apparatus that includes a chamber in which an optical element, including a capping layer, is arranged, and that exposes a substrate to exposure light via the optical element. The apparatus includes a supply unit configured to supply a material into the chamber and a providing unit configured to provide electromagnetic waves to the capping layer. The apparatus is configured so that the electromagnetic waves provided by the providing unit cause a photochemical reaction of the material, to grow a layer on the capping layer, with at least one of a condition of supply of the material by the supply unit and a condition of provision of the electromagnetic waves by the providing unit being changed in accordance with each position of the capping layer, based on information of a decrease in an amount of the capping layer at each position, so as to repair the capping layer.