PURPOSE: To improve th durability of a movable vane by providing delaying means for making slower the closing speed of the movable vane just before the movable vane is brought into contact with a stopper for regulating the closing position of the movable vane at the time of closing the movable vane for controlling the flow velocity of exhaust gas flowing in a turbocharger.

CONSTITUTION: A turbocharger has an exhaust gas turbine 5 turned by exhaust gas supplied from an engine 1 through an exhaust gas passage 23, and the exhaust gas turbine 5 includes a plurality of movable vanes 31 for changing the flow velocity of exhaust gas. In this case, the movable vanes 31 are driven by an actuator 33 having an actuating chamber 37 which is switched and connected to a suction passage 13 by a pipeline 43 having a control valve 45 or to the air by a pipeline 51 having a throttle 53 through a directional control valve 49. When the movable vane 31 is closed, the directional control valve 49 is controlled and switched to the side for connecting the actuating chamber 37 to the pipeline 51, whereby the closing speed of the movable vane 31 can be decreased by operation of the throttle 53.