PURPOSE: To contrive safety in operation as well as the improvement of productivity by a method wherein a vacuum chamber is provided with an opening on one side wall thereof and crusibles are inserted alternately from said openings by two sets of extracting trucks.

CONSTITUTION: An extracting truck 10A is advanced into a space below the floor plate of a vacuum chamber 1 by extending the cylinder 31 of the same whereby a crusible on a table 15 is inserted into the vacuum chamber 1. In this case, a blind plate 124 is adhered to the opening 9 of the vacuum chamber 1 and blockades said opening 9 tightly. Then, the vacuum chamber is evacuated and a metallic material in the crusible 11 is smelted by an induction heating coil 20 under a vacuum. The crusible 11 is inclined about a pin 17 whereby molten metal is poured into a casting mold. During this period, the crusible 11 of another extracting truck 10B on a replacement truck 28 is prepared fro next smelting while effecting necessary services such as repairing and the like. Upon replacing the crusibles 11 of both extracting trucks 10A, 10B, a cylinder 31A is contracted to move the extracting truck 10a onto the replacement truck 28, then, the extracting truck 10B is opposed to the vacuum chamber 1 by moving it horizontally along a rail 26 and operation same as described above is effected.