An apparatus for quantitatively extruding food material is provided. In this apparatus the material is introduced into the space formed between the periphery of a drum and the side wall of a housing. The drum has an inner chamber between its inner wall and the periphery of a cam. A pair of blades is inserted into slits formed on the drum form a compartment in the outside of the drum and a compartment in the inner chamber.Since the dimensions of the space in the compartment outside of the drum decrease towards the exit port, while the space of the inner chamber increases, the pressure in the space becomes much higher than that of the inner chamber. Thus the air in the material is drawn out of the outer compartment into the inner chamber via a path formed between the recess on the trailing surface of the blade and the wall of the slit. As a result material of a uniform quantity and density, and that has no air entrainment, is extruded from the exit port.