A temperature adjustment mechanism for use in an injection molding machine that shortens a molding cycle time while preventing the occurrence of a stranding phenomenon in an optimum manner. A passage includes an opening arranged near an outer surface of an outlet of an injection nozzle for an injection molding machine. A supply control unit supplies the passage with at least one of cooling air and heating air to selectively eject the cooling medium, the heating medium, and a mixture of the cooling medium and the heating medium near the outer surface of the outlet.