PURPOSE: To form the chill layer of sufficient amount in manufacturing the castings made of cast iron, and to prevent failure such as metal penetration defect to be generated by the presence of the chill promoting agent such as the metal Te of the coating agent for casting.

CONSTITUTION: The manufacturing method of castings made of cast iron where the chill promoting agent such as Te, S, Se and the surface tension improving agent such as Cu and P are coated on the desired part of the die before the molten metal is poured in the die, and then, the molten metal is poured in the mold to execute the casting is provided, and the coating agent for casting where the chill promoting agent which contains the chill promoting substance such as Te, S, Se, and the surface tension improving agent which contains the surface tension improving substance such as Cu and P to be used in this manufacturing method is provided.