To improve the accuracy of the molten metal feed temperature in a casting machine employing a method in which a raw material for one charge is melted for each casting, and successively fed to a die.

Before charging the raw material into a melting tank 2, the temperature of the melting tank 2 is measured by using a radiation thermometer 12, and the atmospheric temperature in a housing 6 is measured by using a thermocouple 13. A control device 10 determines the set value of the heating quantity of the present time based on the difference between the actual temperature and the target temperature of the molten metal at the previous heating completion time, the difference between the previous temperature and the present temperature of the melting tank 2 before charging the raw material, and the difference in the atmospheric temperature. After charging the raw material in the melting tank 2, an induction heating coil 3 is started to melt the raw material. The control device 10 stops the induction heating coil 3 when the heating quantity reaches the predetermined value. After measuring the actual temperature of the molten metal at the heating completion time using a radiation thermometer 11, a molten metal feed port 7 is opened, and the melting tank 2 is tilted to pour the molten metal in the die.