PURPOSE: To make unidirectional solidification possible, and obtain uniform test pieces from the same molten metal by providing a check valve in the lower part of a test piece metal mold and so constituting the same that a nozzle opens when the tip of said check valve abuts on the bottom of a melting furnace.

CONSTITUTION: A test piece metal mold 3 is suspended from a wire rope 1 by means of hinges 2, and is immersed into the molten metal 5 in a melting furnace 4. When the tip of a check valve 6 in the lower part of the mold 3 abuts on the bottom of the furnace 4, a clearance is created between a nozzle 7 and the valve 6, and the molten metal 5 goes into the mold 3. When the mold 3 is hoisted upon sufficient entrance of the molten metal 5 into the mold 3, the valve 6 closes the nozzle 7, thereby preventing the outflow of the molten metal and obtaining a test piece casting 8. Since the molten metal enters the mold 3 in the bottom part of the furnace 4, the inclusion of gases and foreign matter does not occur. By the immersion of the removed mold 3 quickly into cooling liquid, forceful unidirectional solidification is developed and the uniform test piece is obtained.