To enhance a yield in the manufacture of the semiconductor by preventing a film thickness of a wafer, uniformity within the face and uniformity between the faces among wafers from being aggravated due to a change of a plasma state in a plasma chamber which originates from the oxidation of an electrode and the contraction of the length of the electrode installed in a process tube used in a decompression vapor deposition apparatus that uses plasma in an apparatus for manufacturing a semiconductor device.

The apparatus for manufacturing the semiconductor device including the decompression vapor deposition apparatus that uses the plasma has a heater 6 provided in the periphery of a treatment chamber 4, and an electroconductive electrode 12 which is vacuum-sealed in a protection pipe 11 installed in the treatment chamber 4.