PURPOSE: To reduce the oxidation of molten metal and to produce a high quality casting by arranging a seal part for shutting off the continuity of the inner and the outer parts of a slide nozzle caused by gap at the approaching position of the slide nozzle to a molten metal pouring hole in a mold.

CONSTITUTION: A molten metal pouring nozzle 2 is arranged at the bottom part of a ladle 1. This is sealed with a stopper rod 3 by descending a cylinder 4a to hold the molten metal. The pouring nozzle 2 is opened with the stopper rod 3 to pour the molten metal into the pouring hole 8 in the mold. A projecting part 5 is extendedly arranged at the lower part of the pouring nozzle 2. The slide nozzle 14 is fitted to the projecting part 5 in the condition of a little gap and executes the approach and the separation to the pouring hole 8 in the mold with a fitting cylinder 4b as the shifting means. A sealing member 17 is brought into close contact with the upper end part of the slide nozzle 14, and the slide nozzle 14 shuts off the continuity of the inner and the outer parts of the slide nozzle 14 with the gap at approaching position to the pouring hole 8 in the mold. By this constitution, the flow-out of the molten metal from the gap can be restrained without giving any damage to the slide nozzle and the projecting part.