Method of Purifying Metal

A method for purifying a metal, comprising:

• a first step of holding a first molten metal containing impurities in a first crucible;
• a second step of immersing a first cooling body in the first molten metal held in the first crucible while letting a cooling fluid flow in the interior of the cooling body to crystallize a first purified metal on a surface of the cooling body;
• a third step of taking out the first cooling body with the first purified metal crystallized thereon from the first molten metal;
• a fourth step of holding in a crucible a second molten metal having an impurity concentration less than that of the first molten metal of the first step;
• a fifth step of melting the first purified metal crystallized in the second step and holding the molten metal in a second crucible together with the second molten metal held in the fourth step;
• a sixth step of immersing a second cooling body in the second molten metal held in the fifth step while letting a cooling fluid flow in the interior of the cooling body to crystallize a second purified metal on a surface of the cooling body;
• and
• a seventh step of taking out the second cooling body with the second purified metal crystallized thereon in the sixth step from the second molten metal;
• wherein the sixth and seventh steps are carried out a plurality of times, with repetition of the first through fifth steps a plurality of times, by adding and melting in the first crucible an impurity-containing metal of an amount equal to the amount of the first purified metal crystallized in the first through fifth steps.