The injection molding machine comprises the closing mechanism 5 having the nozzle touch member 3 to close the tip opening 1a of the nozzle 1 and the electric heater 6 to regulate the temperature of the nozzle touch member 3. The closing member 5 is constituted in such a manner as the arm 13 is pivotally supported on the jacket cover 11 mounted on the nozzle 1, the cylinder 7 is mounted on mounting member 14 provided at the tip of the arm 13, and the nozzle touch member 3 is supported at the tip of the piston rod 7a. The electric heater 6 is arranged around the nozzle touch member 3. When the arm 13 is rotated from the retreated position R to the closed position C by the actuation of the rotor 8, the nozzle touch member 3 is faced to the tip opening 1a of the nozzle 1, and by extending the cylinder 7, the nozzle touch member 3 regulated to the temperature suitable for the resin material by the electric heater 6 closes the tip opening 1a from its front surface.