A device that detects a steering angle of a vehicle and controls a deflection of an irradiation direction of a vehicle lamp based on the detected steering angle, the device comprising: a target angle calculating unit that calculates a target angle of the irradiation direction of the vehicle lamp based on the steering angle; a swivel deflection angle calculating unit that calculates a difference angle between the target angle and a current deflection angle, and then calculates a new deflection angle of the irradiation direction of the vehicle lamp based on the difference angle; and a swivel control unit that controls the deflection of the irradiation direction of the vehicle lamp, characterized in that the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the target deflection angle or a corrected deflection angle, the device further comprising: a swivel deflection angle correcting unit that calculates the corrected deflection angle based on a comparison of the difference angle with a limit angle; and a limit angle setting unit that sets the limit angle and outputs the limit angle to the swivel deflection angle correcting unit; wherein when the difference angle is equal to or smaller than the limit angle, the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the target angle, and when the difference angle is larger than the limit angle, the swivel deflection angle correcting unit calculates the corrected deflection angle by adding or subtracting the limit angle to or from the current deflection angle, and the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the corrected deflection angle. a target angle calculating unit that calculates a target angle of the irradiation direction of the vehicle lamp based on the steering angle; a swivel deflection angle calculating unit that calculates a difference angle between the target angle and a current deflection angle, and then calculates a new deflection angle of the irradiation direction of the vehicle lamp based on the difference angle; and a swivel control unit that controls the deflection of the irradiation direction of the vehicle lamp, characterized in that the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the target deflection angle or a corrected deflection angle, the device further comprising: a swivel deflection angle correcting unit that calculates the corrected deflection angle based on a comparison of the difference angle with a limit angle; and a limit angle setting unit that sets the limit angle and outputs the limit angle to the swivel deflection angle correcting unit; wherein when the difference angle is equal to or smaller than the limit angle, the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the target angle, and when the difference angle is larger than the limit angle, the swivel deflection angle correcting unit calculates the corrected deflection angle by adding or subtracting the limit angle to or from the current deflection angle, and the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the corrected deflection angle. a swivel deflection angle correcting unit that calculates the corrected deflection angle based on a comparison of the difference angle with a limit angle; and a limit angle setting unit that sets the limit angle and outputs the limit angle to the swivel deflection angle correcting unit; wherein when the difference angle is equal to or smaller than the limit angle, the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the target angle, and when the difference angle is larger than the limit angle, the swivel deflection angle correcting unit calculates the corrected deflection angle by adding or subtracting the limit angle to or from the current deflection angle, and the swivel control unit controls the deflection of the irradiation direction of the vehicle lamp, based on the corrected deflection angle.