Abstract: A continuous kneading machine capable of achieving selfcleaning, improvement in kneading efficiency, and reduction in abrasion of paddles is provided. This continuous kneading machine is characterized in that sectional shape of one paddle in a section perpendicular to a rotation shaft is formed of n (where n is an integer, and n.gtoreq.2) pairs of major radius parts and minor radius parts which are alternately arranged with equal angle and formed by a gentle curve, and that sectional shape of another paddle is formed of m (where m is an integer, m.gtoreq.2, and n.noteq.m) pairs of major radius parts and minor radius parts which are formed by an escribed envelope curve drawn by rotation in cooperation with the one paddle, and in which rotation of another paddle is performed in a direction different from the one paddle at a different ratio of rotation frequency.