An illumination device for a motor vehicle includes a light source constructed of a number of semiconductor diodes which generate light in a first predetermined wavelength range, and a conversion layer on which a light beam generated from the light of the light source falls and by which the light beam is changed into a converted light beam. The light of the light beam is converted into a second predetermined wave length range by a converting material. The illumination device is designed such that a predetermined light distribution from the converted light beam is generated at a distance from the illumination device. The illumination device is characterized in that a structure having one or more walls with a predetermined depth in the direction of the thickness of the conversion layer is provided in at least one partial region of the surface of the conversion layer.