Abstract: A wafer transfer device is intended to transfer wafers between a wafer boat in which a plurality of wafer support plates are vertically arranged at regular intervals and a cassette in which a plurality of wafer-mounted levels are vertically arranged at regular intervals. Each of the wafer support plates is ring-shaped having an opening in the center thereof and a passage is defined by openings of the wafer support plates, extending vertically in the boat. The wafer is horizontally transferred into and out of the wafer boat between the wafer support plates by a fork. The fork can be moved in vertical and horizontal directions and it can also be swung. A wafer push-up disk is arranged movable up and down through the passage in the boat. Three wafer supports are projected from the top of the push-up disk. These projections on the push-up disk are arranged contactable with the underside of the wafer without interfering with the fork.

Abstract: A substrate transfer device containing an arm support member for supporting plural substrate support arms at one ends thereof, said arms having substrate housing areas at the other ends thereof, a structure arranged on a base to freely move in the longitudinal direction of the substrate support arms while holding the arm support member, another arm support member for holding a substrate support arm at the other side of the first arm support member, a structure arranged on the base to freely move in the longitudinal direction of the one substrate support arm while holding the arm support member for one substrate, a structure for moving the base up and down, and a structure for moving the base in a direction perpendicular to the substrate support arms on a plane parallel to the plane in which the substrate support arms are included.