Illumination device of a motor vehicle headlamp comprising a projection optics system and a light source unit, the light source unit comprising a surface, wherein - the light source unit can generate a light image on the surface, wherein the light image which can be generated on the surface can be projected in front of the illumination device in the form of a light distribution by means of the projection optics system, wherein - the light source unit comprises a carrier structure, wherein - the carrier structure has an opening, the opening being arranged and designed to match the surface and the light image being capable of being generated at least on a side of the surface facing the projection optics system, wherein - the projection optics system has guide elements and the support structure has elongate guides corresponding to the guide elements, the guide elements being arranged in the elongate guides such that they can be guided along a longitudinal direction of the elongate guides, wherein - the projection optics system rests on the support structure, is movable along the longitudinal direction and can be fastened to the support structure, wherein the projection optics system is movable within a range of movement defined by the length of the elongate guides and the projection optics system has a mounting region and the support structure has a counter-region corresponding to the mounting region, wherein the movement area, fastening area and the counter area correspond to one another in such a way that the projection optics system can be fastened to the support structure in any position within the movement area in such a way that the fastening region of the projection optics system is at least partially fastened to the mating region of the support structure, wherein the fastening region has at least two, preferably three through openings (120, 121, 122) and the mating region has at least two, preferably three receptacles (330, 331, 332), wherein each receptacle (330, 331, 332) corresponds to a respective through opening (120, 121, 122), wherein different receptacles (330, 331, 332) correspond to different through-openings (120, 121, 122), wherein the fastening region can be fastened to the mating region by means of at least two, preferably three fastening elements (6a, 6b, 6c), for example screws, which can be received in the through-openings (120, 121, 122) and in the receptacles (330, 331, 332), and wherein the through openings (120, 121, 122) are elongated and extend in the direction of the optical axis, characterized in that the support structure has arms, wherein the arms of the support structure project in the direction of the projection optics system, wherein the elongated guides are formed in the arms, and the projection optics system has projecting tabs, wherein the guide elements are arranged on the projecting tabs. - the light source unit can generate a light image on the surface, wherein the light image which can be generated on the surface can be projected in front of the illumination device in the form of a light distribution by means of the projection optics system, wherein - the light source unit comprises a carrier structure, wherein - the carrier structure has an opening, the opening being arranged and designed to match the surface and the light image being capable of being generated at least on a side of the surface facing the projection optics system, wherein - the projection optics system has guide elements and the support structure has elongate guides corresponding to the guide elements, the guide elements being arranged in the elongate guides such that they can be guided along a longitudinal direction of the elongate guides, wherein - the projection optics system rests on the support structure, is movable along the longitudinal direction and can be fastened to the support structure, wherein the projection optics system is movable within a range of movement defined by the length of the elongate guides and the projection optics system has a mounting region and the support structure has a counter-region corresponding to the mounting region, wherein the movement area, fastening area and the counter area correspond to one another in such a way that the projection optics system can be fastened to the support structure in any position within the movement area in such a way that the fastening region of the projection optics system is at least partially fastened to the mating region of the support structure, wherein the fastening region has at least two, preferably three through openings (120, 121, 122) and the mating region has at least two, preferably three receptacles (330, 331, 332), wherein each receptacle (330, 331, 332) corresponds to a respective through opening (120, 121, 122), wherein different receptacles (330, 331, 332) correspond to different through-openings (120, 121, 122), wherein the fastening region can be fastened to the mating region by means of at least two, preferably three fastening elements (6a, 6b, 6c), for example screws, which can be received in the through-openings (120, 121, 122) and in the receptacles (330, 331, 332), and wherein the through openings (120, 121, 122) are elongated and extend in the direction of the optical axis, characterized in that the support structure has arms, wherein the arms of the support structure project in the direction of the projection optics system, wherein the elongated guides are formed in the arms, and the projection optics system has projecting tabs, wherein the guide elements are arranged on the projecting tabs.