Arbitrary pieces of semiconductor wafers are supported flexibly on either the upper side or the lower side. The present invention is a thin plate container for supporting plural semiconductor wafers for use in carriage, storage, processing, etc. It comprises processing trays plurally stacked in a state of each supporting at least one semiconductor wafer individually and a coupling mechanism for integrally coupling the processing trays in a state where the processing trays are plurally stacked and separating the processing trays at an arbitrary location. Each processing tray has a one-side support for supporting at least one semiconductor wafer on its one side and the other-side support mutually fitted to the one-side support of the other processing tray on the other side to form a housing space sealed off from the external environment for constraining and supporting the thin plate. Accordingly, as many processing trays as the number of the semiconductor wafers are stacked to constitute the thin plate container.