Polycrystalline silicon manufacturing apparatus and polycrystalline silicon manufacturing method

A polycrystalline silicon manufacturing apparatus comprising a reactor whose inside is sealed by a bell jar and a disc-like base plate, wherein

• the base plate comprises:
• electrode pairs adapted for holding a plurality of silicon cores and applying current to the silicon cores;
• and at least one gas supplying nozzle adapted for supplying a source gas to a space inside of the bell jar,
• all of the electrode pairs are located inside of an imaginary concentric circle C having a radius c and outside of an imaginary concentric circle B having a radius b that is smaller than the radius c, the imaginary concentric circles C and B being imaginary concentric circles centered at a center of the base plate, the imaginary concentric circle C having an area S (=S0/2) that is half an area S0 of the disc-like base plate, the imaginary concentric circle B having the same center as that of the concentric circle C,
• all of the gas supplying nozzle is located inside of an imaginary concentric circle A having a radius a that is smaller than the radius b, the imaginary concentric circle A having the same center as that of the concentric circle C,
• a difference between the radius b and the radius a is in a range of 20 cm to 50 cm, and
• one of the gas supplying nozzles is located at the center of the base plate.