A kneading apparatus includes a barrel having a chamber, which is a tubular hollow, a biaxial screw set for extruding a material to be kneaded downstream by rotation of the biaxial screw set inside the chamber, and kneading blade sections, mounted in the screw set, for kneading the material by shearing the material in tip clearances and a wedge-shaped space between an inside wall of the chamber and the kneading blade sections. The tip clearance becomes narrower from the upstream side to the downstream side in the direction of extrusion of the material. The kneading apparatus, which performs a continuous kneading operation, makes it possible to set proper kneading conditions in accordance with changes in the state of a material being continuously kneaded, and achieves high kneading efficiency.