PURPOSE: To execute a cleaning at the molecule level on the rear surface of a substrate by a method wherein the rear surface of the substrate is supported so as to hold the substrate horizontally and the rear surface of the held substrate is irradiated with ultraviolet rays.

CONSTITUTION: A substrate holding member 3 horizontally supports the end edge part on the rear surface of a substrate 2 by a protrusion part 6 which protrudes to the inside from a frame body 4. A plurality of ultraviolet lamps 12, 14 are arranged respectively at the upper part and the lower part of the substrate 2 which has been placed on the substrate holding member 3. Ultraviolet rays from the ultraviolet lamp 12 are shone at the nearly whole region on the rear surface of the substrate 2 excluding the end edge part which is shielded by the protrusion part 6. Thereby, it is possible to restrain particles from being produced when the substrate 2 comes into contact with the holding member 3, to restrain electrification when the substrate is exfoliated, to prevent the substrate from being contaminated with fine particles and to perform the irradiation of the rear surface of the substrate with the ultraviolet rays efficiently.