PURPOSE: To display an adequate effect of exhaust brake in accordance with a road condition by variably setting the small opening side stop position of an exhaust brake valve, in the case of a device in which the exhaust brake effect is generated by placing the exhaust brake valve in the small opening side stop position.

CONSTITUTION: In the case of an exhaust brake valve 14 turnably provided, with an axis 12 serving as a supporting point, halfway an exhaust pipe 10, a lever 16, which can be moved between positions where the lever 16 is stopped by an opening side stopper 22 and by the closing side first stopper 24, is provided in an end part of the axis 12 protruded to the outside of the exhaust pipe 10. A rod 20, formed as an integral unit with a diaphragm 28 of an exhaust brake unit 18, is connected to this lever 16. A negative pressure chamber 32 of the unit 18 is connected to the atmosphere or a vacuum tank 60 through a vacuum solenoid valve 38. While the closing side second stopper 34 is integrally provided in the rod 20, and an advance-retracting position of the stopper 34 can be adjusted by actuating a negative pressure type actuator 44 to advance- retract by screw a rod 40 through rods 46, 42.