To surely function independently of the condition of road surface or weather and avoid erroneous adjustment of a lighting distance by forming sensor devices into slant sensors.

Sensor devices 24, 28, 30 are connected to an evaluation device 32, and an adjusting device 20 is also connected to the evauation device 32. By this adjusting device 20, a headlight 10 can be rotated centering around an axis 11 in the horizontal direction. The sensor devices 24, 28, 30 are formed into slant sensor devices, and by these slant sensor devices, angles positioned in fixed measuring planes between prescribed fitting planes and the direction of gravity are detected. The slant sensors 24, 28, 30 have pendulums for example, this pendulum can be rotated centering around the axis extending perpendicularly to the measuring plane, it is pulled in the direction 44 of gravity by the dead weight, and relative displacement of the pendulum against the fitting plane is obtained.