Patent attributes
A main body may have a cavity for storing a plurality of parallel semiconductor wafers and an opening for transferring one or more semiconductor wafer into or from the cavity. A covering body may be mounted detachably to the opening in order to close the opening. A gasket may seal between an edge portion of the covering body and an edge portion of the opening. The gasket may be configured such that, when the opening is closed by the covering body, a size of a deformation margin of the gasket is formed to be smaller in a region that seals a vertical edge portion of the opening orthogonal to the face of each semiconductor wafer than in a region that seals a horizontal edge portion of the opening parallel to the face of each the semiconductor wafer.