A molding device includes a lower mold unit and an upper mold unit. A molding cavity is defined between the mold units. The lower mold unit has a storing chamber connected to the molding cavity. The upper mold unit has a damper chamber connected to the molding cavity. A pressurizing rod is inserted into the damper chamber. The pressurizing rod is actuated by a cylinder. When a pushing rod pushes molten metal in the storing chamber to the cavity, an excess amount of the molten metal enters the damper chamber. Therefore, the molding operation is reliably performed even if an excessive amount of molten metal is injected into the storing chamber. Further, the pressurizing rod pressurizes the excess amount of metal in the damper chamber.