Abstract: A substrate-supporting rod (4) comprises a resin body (41) and a metal rod (43). The resin body (41) includes a body portion (411) being cylinder-shaped and having a first through hole (413) in a direction of the axis thereof and a number of shelves (415, 415?) arising from said body portion (411) and extending in parallel and inwardly of a cassette (5) at a predetermined pitch. The metal rod (43) is received in the first through hole (413) of the body portion (411) so as to increase the rigidity of the substrate-supporting rob (4). A projection (4151) is defined on the end of each shelf (415, 415?) to support a substrate (45). Further, the body portion (411) is molded from an electrically conductive resin so that not only the cassette (5) can be protected against static discharge but also resin material is saved and cost is decreased.