An exposure device has a cylindrical peripheral wall member. The peripheral wall member forms a processing space in which a substrate is storable and has an upper opening and a lower opening. Further, a light emitter is provided in an upper portion of the peripheral wall member to close the upper opening. A lower lid member that is provided to be movable in an up-and-down direction and configured to be capable of closing and opening the lower opening is provided below the peripheral wall member. The atmosphere in the processing space is replaced with an inert gas with the substrate stored in the processing space and the lower opening closed by the lower lid member. In this state, vacuum ultraviolet rays are emitted to the substrate from the light emitter, and the substrate is exposed.