To restrain fading and to improve the casting quality and the productivity by using inert gas atmosphere in a small ladle, at the time of automatically pouring molten metal into a mold by receiving cast iron in a pressure type molten metal pouring furnace into the small ladle, adding an inoculant and executing a spheroidizing treatment thereto.

The upper part of the small ladle 17 in the automatic molten metal pouring apparatus is tightly closed with a cover 18 and also, inert gas 3 is supplied from an introducing pipe and the inner part of the small ladle is made in the inert gas atmosphere. Further, an opening hole 11 for inserting a pouring nozzle 9 into the small ladle cover 18 is made of a graphite material and an interval between the opening part 11 and the pouring nozzle 9 is sealed with a seal material of glass wool. Through the molten metal 2 is not sufficiently sealed, but the inert gas atmosphere is held by introducing the inert gas 3 and the molten metal 2 is not brought into contact with the air to be introduced and held in the small ladle. Further, the pouring nozzle 9 in the pressure type molten metal pouring furnace is made slidable in the small ladle opening hole part 11, and the small ladle 17 can be made to be in close contact with or separate from the mold at each time of pouring the molten metal into the mold 8.