A device providing a live three-dimensional image of a speciment

The beam of particles from the primary source is led to the secondary source (1) and a tilting and simultaneously scanning unit (2) placed above the objective (3) is inserted to the path of the output beam of particles with an axis (5). The tilting and scanning unit (2), seen in the direction from the viewed specimen (4) upwards, consists of a bottom stage (2.2) and a top stage (2.1). The top stage (2.1) and the bottom stage (2.2) consist of at least two tilting and scanning elements (6, 7) arranged to create fields orthogonal to each other in the area where the beam of particles with the axis (5) passes through them. Both the output of the first adjustable source (6.1) of a direct tilting signal and the first adjustable source (6.2) of an alternating scanning signal are connected to the first tilting and scanning element (6). Both the output of the second adjustable source (7.1) of a direct tilting signal and the second adjustable source (7.2) of an alternating scanning signal are connected to the second tilting and scanning element (7).