SEMICONDUCTOR DEVICE MANUFACTURING DEVICE

PURPOSE:To perform etching having superior uniformity by a method wherein a semiconductor device manufacturing device, which has a plurality of gas blow-off ports in a chamber, has mechanisms capable of modifying the arrange ment of the gas blow-off ports. CONSTITUTION:A modification of the arrangement of gas blow-off ports is made possible by moving first and second gas distributions 111 and 112, which respectively have first and second upper and lower expanding and contracting mechanisms 109 and 110 in the interior of an upper electrode cover 108. Accordingly, in the case where different kinds of film are continuously etched, the arrangement of the gas blow-off ports is made so that the uniformity of the etching of each kind of the film is most favorably attained, whereby the etching having superior uniformity becomes possible.