An exterior rear view mirror of an exterior rear view mirror assembly for a motor vehicle is described. The exterior rear view mirror includes: an exterior rear view mirror housing, a base bracket, at least partly accommodated in the exterior rear view mirror housing, a frame with walls, which surround an opening arranged on the rear side of the exterior rear view mirror housing, for a mirror glass, and an adjusting device, attached to the base bracket, for the mirror glass. The frame is attached to the adjusting device. In addition, a process for assembly of an exterior rear view mirror of this type is described.