Abstract: The invention relates to a device for alignment of a first component (1; 25) and a second component (2; 26) in a predetermined relation to each other, comprising first measuring unit (7; 7′; 7″) arranged to be mounted on said first component (1; 25) and comprising a light-source (9) for generation of light-radiation (10; 10′) with a predetermined pattern in direction towards a second measuring unit (11; 11′) arranged to be mounted on said second component (2; 26) and also comprising a second light-source for generation of light radiation (13; 13′) with a predetermined pattern in direction towards said first measuring unit (7; 7′; 7″), were each of the measuring units (7, 11; 7′; 7″, comprises a detection device for emitted light radiation.