PURPOSE: To provide the titled device becoming capable of automatic fall of moldings, by simplifying the construction of metal mold equipped with plural extruding plates respectively carrying out different actuation on the movable platen side of injection molding machine main body.

CONSTITUTION: A molding 17 is released from a mold by a method wherein ejector rams 5 and 8 are moved to the direction of extrusion at the same time, and the ejector rod 14 via extruding plate 6, extruding rod 10 and ejector plate 12 from ram 5, and the ejector rod 15 via extruding plate 7, extruding rod 11 and ejector plate 13 from ram 8 are moved to the right hand direction at the same time. Then, the ram 5 is continuously made to carry out the operation of extrusion, the ram 8 is made to stop the operation of extrusion, and moldings 17 are extruded within the ejector rod 14 and the ejector rod 15 is stopped. The moldings 17 are easily taken out according to automatic fall, etc. without interfering with the inside ejector rod 15.