To improve the biting properties of a ground raw material and realize the improvement of the processing efficiency and, at the same time, the stable operation of a screw type kneader extruder by a method wherein the ground raw material is suckingly fed by being forcibly exhausted through an exhaust port provided in the transport part of the screw type kneader extruder.

By driving an exhaust blows 5, air flow is generated from a chute 3 through the raw material feeding port 1a and the bore of a cylinder 1 to an exhaust port 1b. Ground raw material 20 fed from a hopper to the chute 3 flows together with the air flow from the chute 3 through the raw material feeding port 1a into a cylinder 1 and then easily in the flute of a transport screw 2a. The ground raw material 20 is successively sucked in the cylinder 1 or in the flute of the transport screw 2a. Further, the air in the ground raw material 20 is separated through a screen 4a from the ground raw material 20 so as to leave the material, the bulk density of which becomes larger, in the flute of the transport screw 2 and to exhaust the separate air through the exhaust blower 5 from a separator 4.