A multi-shaft kneading machine includes a channel and two screws rotatable around first axes of rotation. A pair of gate rods sandwich the two screws and are rotatable around second axes of rotation. Each of the pair of gate rods has two recess parts that form respective spaces through which the two screws penetrate. Each of the pair of gate rods has a first contact surface, which comes into surface contact with a screw when a gate rod is rotated to a minimum degree-of-opening position. Large diameter parts are fitted into the groove of the cylinder, and a small diameter part have a radius of curvature equal to half a distance between two second axes of rotation and smaller than a radius of curvature of the large diameter parts. The small diameter parts of the pair of gate rods are in contact with each other.