To stably insure the lighting range of a headlight even if a banking angle, a steering angle, or the like is changed, by providing a control part correcting the angle of an optical axis through an actuator, based on respective direction correcting quantities.

Potentiometers 121, 122 are straight line type potentiometers, they are provided on the suspensions of a front wheel and a rear wheel, so as to detect stroke length. A control part 24 is a microcomputer housing an optical axis controlling program, it searches for a pitch angle direction correcting quantity Dpy, a banking angle direction correcting quantity Dbx, and a steering angle direction correcting quantity Dsz based on a pitch angle θb, a steering angle θs, and vehicle speed (v), detected by the potentiometers 121, 122, an angular velocity sensor 14, a steering angle sensor 16, and a vehicle speed sensor 18, and it outputs pulse signals. Step motors 22x, 22y, 22z rotate the optical axis normally or reversely by fixed angles according to the pulse signals output from the control part 24.