PROBLEM TO BE SOLVED: To provide an aseptic joining device capable of smoothly performing aseptic joining work of tubes by allowing a user to check whether or not a heating plate member is present in a cassette disposed in a housing before joining work of tubes, and allowing the user to non-visually check that the cassette is stored in a predetermined accurate position in the housing and that the heating plate member is stored in a correct attitude in the cassette.SOLUTION: A presence/absence detecting sensor 101 for wafers (heating plate members) detects whether or not a wafer WF is stored in a wafer cassette WC that has been positioned at a predetermined position in a cassette storage unit 82. As long as an innermost wafer WF in the wafer cassette WC is stored in a correct attitude in the wafer cassette WC, the presence/absence detecting sensor 101 outputs a signal 202S representing that the wafer WF is present in the wafer cassette WC.
