A headlamp is provided with a lamp unit provided in a lamp housing formed by a lamp body and a transparent cover for covering a front side of the lamp body. The lamp unit is supported in the lamp housing in a suspending state in such a condition that the lamp unit can be swung in vertical and horizontal directions. An output shaft coupled to a lower end of the lamp unit can be rotated around its axis and slide in a direction perpendicular to the axis. A rotation of the output shaft around its axis is transmitted to the lamp unit. By a movement of the output shaft in the direction perpendicular to the axis, a rotation between the output shaft and the lamp unit causes.