(57) An optical axis adjusting apparatus of a projector type headlight (10) including a bracket (34, 36) for supporting a frame (22) integrally fixed with the lamp unit composed of a reflector (12), a light source (16), a shade (18) for shaping the light reflected by the reflec­tor (12) and condensed at a predetermined region suitably, and a convex lens (20) for forwardly projecting the shaped light. The bracket's position is adjustable with respect to the lamp hous­ing, and the bracket supports the frame rotatably around the horizontal and vertical axes perpendicular with respect to the reflector's axis (Z-Z). The rotation around the horizontal axis (X-X) is effected by an adjusting screw rod (63) which is screwed to a nut (66) fixed at a portion of the frame and rotatable without moving in the reflector's axis direction, and on the other hand the rota­tion around the vertical axis (Y-Y) is effected by another adjusting screw rod (61) which is screwed to a nut (64) fixed at a portion of the bracket and rotatable without moving in the reflector's axis direction with respect to the housing. By this, the direction of the optical aixs of the lamp unit is easily adjusted and the adjusted position thereof is held surely.