| 摘要 |
PURPOSE:To prevent a packing from being deteriorated when it is irradiated with ultraviolet rays, to prevent a sealing property from being worsened, to prevent particles from being produced and to execute a good treatment for a long term by a method wherein an ultraviolet-ray shielding means is installed at the packing for airtight sealing use. CONSTITUTION:A packing for airtight sealing use, e.g. an O-ring 17 composed of a fluorine-based rubber, is installed between an airtight container 2 and a quartz glass sheet 16. A ring-shaped metal film 18 is formed along a contact part with the ring 17 as an ultraviolet-ray shielding means which prevents ultraviolet rays from being radiated to the ring 17. Consequently, ultraviolet rays from an ultraviolet-ray light source are reflected in a multiple manner inside the sheet 16. However, they are reflected by the film 18 and the ring 17 is not irradiated with the ultraviolet rays. Thereby, it is possible to prevent the ring 17 composed of the fluorine-based rubber or the like from being deteriorated when it is irradiated with the ultraviolet rays. It is possible to prevent a sealing property from being worsened and to prevent particles from being produced. As a result, a good cleaning treatment can be executed for a long term. |
