PURPOSE: To make conveyance smooth by forming a pair of side walls along a conveying rail at an interval of a lead forming standard dimension, and positioning the right and left centers of a semiconductor in the captioned device for conveying said semiconductor along said rail.

CONSTITUTION: Side walls 6b, 6b having a gap l of an outside lead molded form standard dimension, are provided along a conveying rail 6 in such a way that they guide the resin part external shape of a semiconductor device 1 and position its right and left centers. Accordingly, any article of deformed dimension of molded form standard of an outside lead is stopped at the part of the side wall 6b, allowing only good articles to pass through. By this construction, conveyance can be made smooth.