NOVELTY - Raw-material metallic silicon is reacted with hydrogen chloride gas, to obtain silicon tetrachloride, which is distilled to obtain highly purified silicon tetrachloride. Polycrystalline silicon is deposited to obtain highly purified polycrystalline silicon by reaction of silicon tetrachloride and zinc. The component in exhaust gas of polycrystalline silicon is separated into a mixture (119) of zinc chloride and unreacted zinc, and unreacted silicon tetrachloride. Zinc (115) and hydrogen chloride gas (111) are obtained from the mixture and used for the respective reactions.    USE - Manufacture of highly purified polycrystalline silicon for solar cells.    ADVANTAGE - The method enables economical manufacture of highly purified polycrystalline silicone with simple operational and apparatus management.    DETAILED DESCRIPTION - Raw-material metallic silicon is reacted with hydrogen chloride gas, to obtain low-purity silicon tetrachloride, which is then distilled to obtain highly purified silicon tetrachloride. The produced polycrystalline silicon is deposited in the reactor to obtain highly purified polycrystalline silicon within reactor by carrying out reaction of highly purified silicon tetrachloride and zinc. The component in exhaust gas of highly purified polycrystalline silicon is separated into a mixture of zinc chloride and unreacted zinc, and unreacted silicon tetrachloride. Zinc and hydrogen chloride gas are obtained from the mixture of zinc chloride and unreacted zinc. The unreacted silicon tetrachloride is transferred to silicon-tetrachloride distillation process and distilled with low-purity silicon tetrachloride. The obtained hydrogen chloride gas and zinc are used for the respective reactions. The mixture of zinc chloride and unreacted zinc is oxidized (201) to obtain a mixture (210) of zinc chloride and zinc oxide. Zinc chloride aqueous solution (211) is obtained by adding the mixture of zinc chloride and zinc oxide to hydrochloric acid aqueous solution (214). Organic solvent containing zinc component (212) and hydrochloric acid aqueous solution (217) are obtained by separating an organic solvent phase and a water phase after contacting zinc chloride aqueous solution and organic solvent (215) containing acidic extractant. The organic solvent containing acidic extractant and zinc sulfate aqueous solution (213) are obtained by separating an organic solvent phase and a water phase after contacting the organic solvent containing zinc component, and sulfuric acid aqueous solution (216). Zinc and sulfuric acid aqueous solution are obtained by carrying out aqueous electrolysis (205) of zinc sulfate aqueous solution. A portion of hydrochloric acid aqueous solution is purified (206). Hydrogen chloride is vaporized (207) from hydrochloric acid purification process to obtain highly purified hydrochloric acid aqueous solution (218) and hydrogen chloride gas. Or, a portion of hydrochloric acid aqueous solution is vaporized. Vaporized hydrogen chloride is purified (208) to obtain hydrogen chloride gas. The other portion of hydrochloric acid aqueous solution is used for dissolution treatment (202). The organic solvent containing acidic extractant is used for zinc extraction (203). The sulfuric acid aqueous solution is used for back extraction (204) of zinc component.    DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart of the zinc regeneration process.    Hydrogen chloride gas (111)    Zinc (115)    Mixture of zinc chloride and unreacted zinc (119)    Oxidation treatment (201)    Zinc component extraction (203)    Zinc component back extraction (204)    Zinc sulfate aqueous solution electrolysis (205)    Hydrochloric acid purification (206)    Vaporization of hydrogen chloride (207)    Purification of hydrogen chloride (208)    Mixture of zinc chloride and zinc oxide (210)    Zinc chloride aqueous solution (211)    Organic solvent containing zinc component (212)    Zinc sulfate aqueous solution (213)    Hydrochloric acid aqueous solution (214,217)    Organic solvent containing acidic extractant (215)    Sulfuric acid aqueous solution (216)    Highly purified hydrochloric acid aqueous solution (218)