NOVELTY - The device comprises a viewport (180) arranged in an upper end of a reaction chamber (130), a power supply unit (160) that supplies electric current and is connected to two standing erect load filaments, a gas supply part (150) that supplies the reaction gas within the reaction chamber, multiple silicone loads (140) consisting of the two standing erect load filaments, and a control unit for controlling an electric energy supplied to the standing erect load filaments through the viewport based on a surface temperature of the silicone load.    USE - The device is useful for manufacturing poly-silicon (claimed), which is useful for manufacturing a solar cell.    ADVANTAGE - The device is capable of energy efficiently manufacturing poly-silicon with high quality, and accurately measures the surface temperature of the silicone loads.    DETAILED DESCRIPTION - The device comprises a viewport (180) arranged in an upper end of a reaction chamber (130), a power supply unit (160) that supplies electric current and is connected to two standing erect load filaments, a gas supply part (150) that supplies the reaction gas within the reaction chamber, multiple silicone loads (140) consisting of the two standing erect load filaments, a horizontal load filament for measuring a surface temperature of a silicone load and horizontally connecting an upper end of the standing erect load filaments, and a control unit for controlling an electric energy supplied to the standing erect load filaments through the viewport based on a surface temperature of the silicone load. The silicone loads form three concentric circles. The viewport is formed in a position corresponding to the concentric circle, and includes a pyrometer. The control unit controls the electric energy so that a surface temperature of the silicone loads is maintained at 1000-1100 degrees C. An INDEPENDENT CLAIM is included for a poly-silicon manufacturing method.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic exploded perspective view of a device for manufacturing poly-silicon.    Reaction chamber (130)    Silicon loads (140)    Gas supply part (150)    Power supply unit (160)    Viewport. (180)