A decanter type centrifugal separator includes a torque transmission mechanism with enhanced effect of absorbing a torsional vibration. The decanter type centrifugal separator (10) includes a bowl (20); a screw conveyor (40) disposed in the bowl (20); a processed liquid feed portion (15); a separated liquid discharge port (81); a solid discharge port (82); a drive portion (71); and a differential gear unit (50) for generating a difference in speeds between the bowl (20) and the screw conveyor (40). A torque transmission mechanism (60, 61) includes an elastic damping member (67) for absorbing the torsional vibration of the screw conveyor (40).