PURPOSE: To prevent a phenomenon such as trailing when a liquid silicone rubber is injection-molded from occurring by designing an injection nozzle so that a temperature boundary generates in a nozzle tip and a sprue is cut near the temperature boundary.

CONSTITUTION: The subject nozzle is composed of a main nozzle system 13 equipped with a cooling means around an outer periphery, and a nozzle tip 18 with a screw attached to the tip. The nozzle orifice 19 at the extreme end of the nozzle tip 18 is formed slightly smaller than the opening of a sprue. A passage 17 between the nozzle orifice 19 and a flow path 15 in the main nozzle system is formed smaller in diameter than the nozzle orifice 19 and a stepped part 20 is formed in the nozzle orifice 19.