PURPOSE: To provide a molding metal mold suitable for a polyester resin by providing a cooling hole and a heat insulating plate in the vicinity of an auxiliary spool connected to a product part formed in a cavity to prevent the occurrence of a pulling phenomenon of the resin upon thermal cracking and mold releasing operations.

CONSTITUTION: A hot runner 104 introduces a molten resin from a channel 102 and passes it to a gate 105. The product part 109 is formed by a cavity 110 and a core 111. The auxiliary spool 112 connecting the gate 105 which formes an outlet of the hot runner 104 to the product part 109, is provided in the cavity 110, and the product 109 is spaced apart from the gate 105 so that the heat from the side of the hot runner does not affect the product. The cooling hole 113 passes a cooling medium such as water or the like to cool the cavity 110 and maintains the auxiliary spool at a predetermined temperature. A heat insulating plate 114 encircling the inlet part of the auxiliary spool 112 is for preventing the heat transfer from occurring between the cavity 110 and a hot bush 101, and the configuration of the heat insulating plate 114 can be selected to a ring shape or an arbitrary shape.