NOVELTY - A silicon refining apparatus consists of crucible (3) containing silicon molten metal (4), heater (2) which heats the crucible, silicon injection portion in which silicon (5) separated from silicon-containing waste liquid is injected into the silicon molten metal, carbon concentration calculation portion which calculates carbon concentration of the silicon molten metal in the crucible, and control portion (8) which controls addition amount of the silicon to the silicon molten metal.    USE - Apparatus is used for refining silicon (claimed) for manufacturing semiconductor wafer for solar cell.    ADVANTAGE - The silicon is economically refined using the apparatus with high purity and without forming insoluble substance e.g. silicon carbide, by simple process.    DETAILED DESCRIPTION - A silicon refining apparatus consists of crucible containing silicon molten metal, heater which heats the crucible, silicon injection portion in which silicon separated from silicon-containing waste liquid is injected into the silicon molten metal, carbon concentration calculation portion which calculates carbon concentration of the silicon molten metal in the crucible, and control portion which controls addition amount of the silicon to the silicon molten metal based on the concentration of carbon in the silicon molten metal calculated by the carbon concentration calculation apparatus. An INDEPENDENT CLAIM is included for silicon refining method, which involves melting silicon, adding silicon separated from the silicon containing waste liquid to the obtained silicon molten metal, calculating carbon concentration of the silicon molten metal, controlling carbon concentration of the silicon molten metal and addition amount of the silicon to the silicon molten metal, and purifying silicone in the silicon molten metal.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic section view of the silicon refining apparatus.    Heater (2)    Crucible (3)    Silicon molten metal (4)    Silicon (5)    Control portion (8)    Discharge portion (11)    Solidification crucible (12)