An adjusting device with a mounting fixture (4) for mounting a wafer (2) on a mounting side (4a) of the mounting fixture (4), whereby the mounting fixture has at least one through-hole (5) directed essentially orthogonal to the mounting side (4a), is characterised in that the through-hole (5) on the mounting side (4a) has a smaller cross-section than on the entrance side (4b) of the through-hole (5) facing away from the mounting side (4a).