NOVELTY - Solid zinc (B1) is supplied to heating chamber of vaporization apparatus (5) through gate valve. The gate valve is closed, and solid zinc is heated to produce zinc gas (G1). The obtained gas and silicon tetrachloride gas (G3) are supplied to reactor (2), and gas (G3) is reduced to produce polycrystalline silicon and zinc chloride gas (G4). Gas (G4) is cooled to produce zinc chloride melt solution (L1). Solution is electrolyzed to produce zinc melt solution (L2). Solution is heated and vaporized to produce zinc gas (G2). Thus, polycrystalline silicon is manufactured.    USE - Manufacture of polycrystalline silicon used for solar cell and electronic devices.    ADVANTAGE - The polycrystalline silicon is efficiently manufactured, and recycling of zinc is enabled.    DETAILED DESCRIPTION - Solid zinc (B1) is accommodated in front chamber of a vaporization apparatus (5) having gate valve, which air-tightly partitions the front chamber and heating chamber used for heating and vaporization of solid zinc. The front chamber and heating chamber are filled with inert gas. The gate valve is opened, and solid zinc is supplied to heating chamber. The gate valve is closed, and solid zinc is heated and vaporized to produce zinc gas (G1). The obtained gas and silicon tetrachloride gas (G3) are supplied to a reactor (2), and gas (G3) is reduced to produce polycrystalline silicon and zinc chloride gas (G4). The gas (G4) is cooled to produce zinc chloride melt solution (L1). The solution is electrolyzed by an electrolyzer (4) to produce zinc melt solution (L2). The solution is heated by another vaporization apparatus (6), vaporized, and zinc gas (G2) is produced. The obtained gas is supplied to reactor through piping (12) extended from apparatus (6). The piping has a non-return valve (19) for preventing inflow of zinc gas (G1). Polycrystalline silicon is continuously produced by intermittently repeating production of zinc gas from solid zinc. The zinc gas (G2) is supplied to reactor from vaporization apparatus (6). Thus, polycrystalline silicon is manufactured. An INDEPENDENT CLAIM is included for production apparatus of polycrystalline silicon (1).    DESCRIPTION OF DRAWING(S) - The drawing shows the block diagram of structure of polycrystalline silicon production apparatus.    Polycrystalline silicon production apparatus (1)    Reactor (2)    Electrolyzer (4)    Vaporization apparatus (5,6)    Piping (12)    Non-return valve (19)    Solid zinc (B1)    Zinc gases (G1,G2)    Silicon tetrachloride gas (G3)    Zinc chloride gas (G4)    Zinc chloride melt solution (L1)    Zinc melt solution (L2)