CONTINUOUS VACUUM TREATMENT DEVICE

PURPOSE:To prevent a work from being damaged by friction with a slit-shaped sealing part by providing non-evacuating preliminary chambers to the atm. side of plural prevacuum chambers before and after a vacuum treatment chamber. CONSTITUTION:A steel sheet F or the like is passed through the plural prevacuum chambers 2, 3 before and after the vacuum treatment chamber and the vacuum degree is gradually increased or lowered at the time of subjecting said steel sheet to a plasma treatment, vapor deposition treatment, etc., in the vacuum treatment chamber. The preliminary chambers 27, 28 which have no evacuation devices are provided to the outside of the atm. side prevacuum chamber and the internal pressure thereof is regulated to >=100Torr at the time when the steel sheet F passes the inside of the slit-shaped seal connecting the respective prevacuum chambers. The pressure gradient in the slit-shaped sealing part constituted of an upper case 13 and a lower case 14 which seal the atm. pressure and the preliminary chambers 27, 28 is then decreased and the pressure difference between the part above the steel sheet and the part below the steel sheet in the slit is decreased. The damage of the steel sheet F by contact with the upper case 13 or lower case 14 for forming the slit is thus prevented.