Method of manufacturing carbon electrode and method of manufacturing fused silica crucible

A method of manufacturing a fused silica crucible, the method comprising:

• a) manufacturing a plurality of carbon electrodes for melting a vitreous silica object to be melted by arc discharge, wherein the levels of impurities of the vitreous silica are set to be in the ranges of 0.001 to 1.0 ppm of Fe, 0.001 to 1.3 ppm of Na, 0.001 to 1.0 ppm of K, 0.001 to 1.0 ppm of Li, 0.001 to 0.05 ppm of Cu, and 0.001 to 1.0 ppm of Ca, or in the ranges at lower levels than these ranges, by rubbing the surface of a carbon electrode of the carbon electrodes, before power is supplied, with a vitreous silica of the same type as the vitreous silica object to be melted, by at least one of:
• inserting a front end side of the carbon electrode into a storage tank storing powdered vitreous silica, by at least one of rotating and reciprocating in an axial direction the storage tank and the carbon electrode relative to each other;
• rubbing the surface of the carbon electrode by ejecting powdered vitreous silica from a nozzle onto the surface of the carbon electrode;
• rubbing the surface of the carbon electrode with a grinder made of vitreous silica;
• and
• rubbing the surface of the carbon electrode against a rotating surface of at least a portion of a fused vitreous silica crucible;
• b) placing a vitreous silica powder into a crucible mold;
• and
• c) creating a discharge between the plurality of carbon electrodes by supplying power.