Abstract: The apparatus comprises a rack containing a casting that includes a core, a heating chamber that includes a vibration structure for vibrating the rack and in a lower portion thereof a first sand discharge structure for discharging sand falling from the casting for removing casting sand and core sand adhering to the casting while heat treating the casting, and a cooling chamber that includes a water tank for immersing the rack containing the casting, an elevator structure for lowering the rack into the water tank and lifting the rack out of the water tank, an oscillation structure for oscillating the rack when the rack is in the water tank, and a second sand discharge structure for discharging sand falling onto a bottom of the water tank for washing off casting sand and core sand adhering to the casting ejected from the heating chamber while cooling the casting.