PURPOSE: To prevent the disturbance of molten metal and to obtain a casting product having little defect by providing a guide groove of the molten metal in the inner wall surface of outer circumference in a molten metal flow direction changing part of a casting mold device.

CONSTITUTION: In the molten metal flow direction changing part 6 of a runner 21, the guide groove 61 is provided in the inner wall surface of the outer circumference part. When the molten metal A rises a molten metal supplying tube 82 and passed through the direction changing part 6, the molten metal is extered into a casting cavity 5 along the guide groove 61 through a flowing weir 211. By the effect of the guide groove 61 in the direction changing part 6, the disturbance is hardly caused, thereby the entanglement of air is prevented.