To provide a roller support device capable of enhancing the operating efficiency of roller mounting/removal.

This roller support device is structured as follows: A kneading roller 16 is rotatably pivoted by a bearing part 12 of a roller holder 11 supported by an inner frame 10 in a freely rotating manner. The axis G1 of the roller holder 11 and the axis G2 of the kneading roller 16 are eccentrically arranged by a gap "d1". The roller holder 11 is rotated by a lever 21, and the lever 21 is urged by the resilient force of a compression coil spring 28 through a rod 23. Further, the distance "d2" between a pin 22 of the lever 21 and a second small shaft 14, is longer than the gap "d1". The compression coil spring 28 loses its resilient force by turning a thumb nut 30 so as to cause the receding of a moving piece 25. Thus, the kneading roller 16 can break away from a swinging roller.