A mechanism for pressing a nozzle 26 of an injection device 10 against a die 33, comprises a hooking device 12 which moves so that a hooking body 23 hooks or does not hook on a to-be-hooked portion 24; and a traction device 11 having, on its one end, the hooking device 12 and having, on its other end, the injection device 10. In this mechanism, the portion of the hooking device 12, opposite to the side adjacent to the traction device 11 is attached to the die 33 in the vicinity of the portion of the die 33, against which the nozzle 26 is abutted.