Optical axes are simultaneously adjusted when a plurality of lighting device units 30, the light sources of which are light emitting elements 34, are tiltably supported by the common unit support member 20. In this case, the positioning recess portion 20d is provided which is composed so that the light source fixing portion 20B1 formed in a plurality of portions of the unit support member 20 can be contacted with the back face 42a and the outer circumferential face 42b of the support plate 42 for supporting the light emitting element 34. Due to the foregoing, the light emitting element 34 can be highly accurately attached to the unit support member 20, and the optical axes A.sub.x, of the lighting device units 30 can be put in order.