PURPOSE: To satisfactorily execute mold release and to manufacture a casting whose external appearance is satisfactory by executing temperature control of a model board so that the temperature of the model board always becomes higher by a specific value than the temperature of molding sand.

CONSTITUTION: By a temperature detector 21, the temperature in the vicinity of the surface of a model board 5 is measured and inputted to a signal converter 31, and outputted to a heater controller 33. On the other hand, by a temperature measuring instrument 13, a temperature of molding sand 11 is measured, inputted to a signal converter 32, and outputted to the heater controller 33. The heater controller 33 calculates and outputs so that a temperature of the model board always becomes higher than this sand temperature within a range of 3-15°C, and a heater 3 is controlled. In the case a temperature of the model board is higher than 15°C, water contained in the molding sand coming into contact with the model board falls and a sand mold comes to easily get out of shape.