NOVELTY - A halogen gas is manufactured by introducing gas into a reaction container in vacuum; generating plasmas in the reaction container to produce a plasma chemical reaction; and removing fine particles produced by the plasma chemical reaction and containing an element other than halogen from the reaction container to generate halogen gas in the reaction container.    USE - For manufacture a halogen gas.    ADVANTAGE - The method allows the halogen gas drawn from the apparatus to be conveyed to the vacuum chamber which accommodates substrates to be processed in a semiconductor manufacturing process.    DETAILED DESCRIPTION - Halogen gas manufacture involves introducing gas of structures AiXj, AkXlOm or ArXsNt into a reaction container in vacuum; generating plasmas in the reaction container to produce a plasma chemical reaction; removing fine particles produced by the plasma chemical reaction and containing an element other than halogen element from the reaction container to generate halogen gas in the reaction container.    A = metallic element or semiconductor element;    X = halo;    i-m = integers; and    r-t = integers.    INDEPENDENT CLAIMS are included for:    (1) an apparatus for manufacturing halogen gas comprising a reaction container (10); gas introduction part which introduces gas into the reaction container; plasma exciting electric field application part which generates plasmas in the reaction container; and a fine particle collecting part which is installed in the reaction container or in a fine particle collection container connecting with the reaction container; and    (2) a halogen gas recovery and circulatory system comprising vacuum chamber accommodates a substrate to be processed; gas separation and refinement mechanism connected to the vacuum chamber and recovers exhaust gas produced during the process in the vacuum chamber, and separates the gas containing halogen element and metallic element or semiconductor element from the exhaust gas to refine it; a pipe (42) connected with the gas introduction part of the apparatus and conveys the separated and refined gas containing halogen element and metallic element or semiconductor element from the gas separation and refinement mechanism to the gas introduction part; and the halogen gas drawing part connected in one part with the apparatus for manufacturing halogen gas and connected in the other part with the halogen gas introduction part of the vacuum chamber.    DESCRIPTION OF DRAWING(S) - The figure is a cross sectional view of the apparatus.    Container (10)    Plate (31)    Gas introducing part (40)    Pipe (42)    Filter (52)