PURPOSE:To improve processing capacity by utilizing the empty weight fall of a wafer through inclination of a tubular body of a plasma etching device consisting of an etching standby chamber equipped with a stopper divided with a switching valve, an etching chamber, a discharge auxiliary chamber, etc. CONSTITUTION:A groove 55 holding the periphery of a semiconductor wafer 10 is provided on a tubular body 30 of a plasma etching device. This body is divided into an etching standby chamber 35, an etching chamber 36 and a discharge auxiliary chamber 37 so that they assume an inclined profile. Under this constitution, wafers are fed one by one to the standby chamber 35 by a wafer feed device 53 and for the rest of process, wafers, by their own dead weight, roll and drop and are sequentially received and transferred by means of a stopper 68-72. Then the processed wafers are recovered by a semiconductor wafer recovery device 62. Thus the processing capacity can be increased and the both sides of the semiconductor wafer 10 be etched simultaneously.