To provide an injection molding die capable of restraining cool- solidification of molten resin flown in the tip end of a pressurized fluid injection device, and thus avoiding the tip end of the pressurized fluid injection device from being clogged even in setting the temperature of the die low for shortening the injection molding cycle.

The die is employed for introducing pressurized fluid from a pressurized fluid injection device 20 installed in the mold into molten thermoplastic resin injected within a cavity 16 provided in the cavity, thereby forming a hollow part in the inside of thermoplastic resin within the cavity 16, and it includes a die member 20 at the adjacent part between it and the tip end 32 of the pressurized fluid injection device 30, and the die member 20 is manufactured of material having a low coefficient of heat conduction.