The present invention includes a method for casting a silicon ingot by using a continuous casting method by means of an electromagnetic induction, and a method for cutting the silicon ingot as a starting material into plural silicon blocks. When the silicon blocks with a square section are cut out, the sectional shape of the silicon ingot is set to be rectangular. Not less than 6 pieces of equal-sized silicon blocks are cut out from the silicon ingot, thereby enabling to enhance the manufacturing efficiency to a great extent. And since the amount of excision of the edge per silicon block is reduced, the production yield can be enhanced. Further, since the proportion of columnar crystals with large grain size inside the ingot can be increased, it becomes possible to enhance the conversion efficiency of a solar battery using the silicon block as a substrate material.