To solve the problem that conventional vehicular headlight has a large-sized and complicated structure for a drive mechanism.

The vehicular headlight has a drive unit 11 which moves the predetermined light distribution pattern LP in almost horizontal direction by rotating a projector lens 4 and a shade 5 around the vertical axis V-V (rotational axis 16). The projector lens 4 and the shade 5 are set up such that the predetermined light distribution pattern LP is irradiated mainly in the direction of the front side of the vehicle, when an axis Z2-Z2 for the projector lens 4 is faced to the inside of the vehicle as its initial state. By rotating the projector lens 4 and the shade 5 in the direction opposite to the orientation of the axis Z2-Z2 for the projector lens 4 in initial state, the predetermined light distribution pattern LP moves to the direction of the outside of the vehicle. As a result, the drive unit 11 can be of small-sized and simple structure, accordingly reducing the manufacturing cost.