PURPOSE: To provide a fixed quantity weighing equipment arranged in an injection molding machine, wherein pulsation of supplying quantity is almost eliminated and rotational resistance of a convey screw is low.

CONSTITUTION: In an injection molding machine, there is provided a device for supplying molding material by a fixed quantity. A supply opening 6 communicated with a hopper 4 and a hopper opening 7 communicated with the inside of an injection cylinder are connected by a horizontal cylinder convey passage 12. A convey screw 9 is arranged in the convey passage 12 so as to conform a rotational axis 15 to the axis core of the convey passage 12. An outer diameter of a flight 10 of the convey screw 9 is reduced with approach to the hopper opening 7. At times, a notch larger than a diameter of a resin pellet to be conveyed is formed on the outer edge of the flight.