A vehicle headlamp in which a light source unit in a lamp body is tiltably supported by an aiming mechanism and aiming is carried out by turning a bevel gear of an aiming screw provided outside the lamp body. The bevel gear is covered by a synthetic resin cap, and the cap is formed with an opening into which a screwdriver is to be inserted, and a lid is continuously formed in the peripheral edge portion of the opening, so that once the lid 46 is folded and covers the opening, the headlamp becomes to comply with the visual aiming specification that prohibits users to perform aiming adjustment of the light source unit.