Vacuum processing system

A vacuum treating apparatus comprising:

• a treating chamber for treating a substrate in vacuum, a plurality of cassettes which hold substrates that are to be conveyed into said treating chamber, said cassettes each including a plurality of holding stages with substrate supports for holding substrates, a plurality of cassette stands for installing respective ones of said cassettes in horizontally spaced relation, mapping means for checking a stage of holding said substrates in said cassettes, means for conveying said substrates between said cassettes and said treating chamber, means which selects either that said substrate which is treated in said treating chamber be held in said cassette from which said substrate was taken out or that said substrate which is treated in said treating chamber be held in another cassette which is different from said cassette;
• and
• wherein said mapping means checks a height of a substrate support in each of said stages of said cassette for recovering said substrates into said cassette, when no substrate exists in said cassette.