A vehicle headlamp is equipped with a shade driving unit 24 for moving a movable shade 22, which is capable of shading part of light incident on a reflector 20 from the discharge light emitting portion 18a of a discharge bulb 18, between at least two positions where the incident light is shed in different degrees. The discharge bulb 18 is fixedly supported by the reflector 30 via a bulb supporting base 26 and the movable shade 22 and the shade driving unit 24 are fitted to the bulb supporting base 26. Thus, the light source bulb 18, the movable shade 22 and the shade driving unit 24 together with the bulb supporting base 26 can be operated integrally as a unit. The unit is prefabricated before being fitted to the reflector 20 to facilitate the assembling of the lamp. Moreover, the precision of placement of the movable shade 22 with respect to the discharge light emitting portion 18a can also be improved.