An optical axis adjusting device for a vehicle headlamp judges an inclined state of the vehicle on the basis of detection of an ultrasonic sensor of a vehicle, and performs an optical axis adjustment of a headlamp. In order to accurately judge the inclined state and to suitably adjust the optical axis of the headlamp, with respect to the detection by the ultrasonic sensor, a factor hindering its accurate detection is detected, and when it is judged that the ultrasonic sensor can not perform an accurate detection, the optical axis adjustment of the headlamp is suspended.