NOVELTY - The device comprises a crucible part having a discharge unit that is penetrated into a side in a direction parallel to a backside, a cast part including a casting space for forming a silicon substrate and extending in the direction parallel to the discharge unit of the crucible part, a dummy bar inserted into the casting space from a side of the casting part, and a cooling part installed at the side of the casting part. The casting part comprises a first cast part that is extended in a vertical direction, and a second cast part that is parallelly extended with the first cast part.    USE - The device is useful for preparing a silicon substrate (claimed) for a solar cell.    ADVANTAGE - The device has reduced energy consumption.    DETAILED DESCRIPTION - The device comprises a crucible part having a discharge unit that is penetrated into a side in a direction parallel to a backside, a cast part including a casting space for forming a silicon substrate and extending in the direction parallel to the discharge unit of the crucible part, a dummy bar inserted into the casting space from a side of the casting part, and a cooling part installed at the side of the casting part. The casting part comprises a first cast part that is extended in a vertical direction, and a second cast part that is parallelly extended with the first cast part and combined with a first slope part, where the length of the first cast part is smaller than the second cast part based on the discharge unit. The cooling part comprises a gas injector for injecting the gas, where the gas is inert gas e.g. helium, argon or nitrogen. The dummy bar is made of single crystal material. The crucible part comprises a first crucible part that includes a second slope part in a direction parallel to the side part, and a second crucible part that is inserted and coupled into an inner side of the first crucible part. The device further includes a gas supply part for supplying the gas to an implantation part, and a source supplying part for supplying the silicon material to the implantation part, where the silicon material and gas are selectively supplied to the implantation part. A shield prevents the external atmosphere from contacting with the silicone molten metal in the casting space. The crucible part is installed within a main chamber. A first valve controls the opening and closing of a raw material pipe and a material feed part. The gas supply part comprises a gas generating part that provides the space to store the inert gas. A second valve is arranged between the gas generating part and a gas service pipe.