Abstract: The disclosure relates to a method for localizing the three-dimensional position of a spot in an object in conjunction with X-ray exposure of the object, in which the object is fixed in a pre-determined position and is exposed by means of an exposure apparatus in two directions each on either side of a center line at a right angle to the plane of the image for obtaining a first print and a second print, the two-dimensional position of the target spot on the two prints being established in relation to an index on the prints, and the coordinates of the spot in relation to the indices being processed to obtain control signals for adjustment of a guidance instrument with means for placing in the target spot in the object.