A gathering operation includes a restraint operation of moving forward a left lower tool retention member so as to restrain a reference lower tool with the left lower tool retention member, an inserting operation of moving forward a right lower tool retention member so as to insert the right lower tool retention member into an insertion hole of a target lower tool, and an execution operation of moving the left and right lower tool retention members along a left-right direction so as to come close with each other. If a failure of the inserting operation is determined, a control device performs a retry operation of moving forward the right lower tool retention member again so as to insert the right lower tool retention member into the insertion hole (141) of the target lower tool after moving backward the left lower tool retention member.

A high-temperature joining furnace is presented, which is designed for example for the diffusion bonding of joining materials such as metals, plastics, ceramics and corresponding workpieces. The joining furnace comprises a heating chamber, a workpiece holder arranged in the heating chamber for receiving a workpiece to be processed in the joining furnace, a pressing device arranged and adapted to apply a pressing force to the workpiece, wherein the pressing device comprises a pressing plate for uniformly applying the pressing force to the workpiece, and is characterized in that the pressing plate is equipped with a pressing plate heating device for heating the pressing plate and/or the workpiece.