The invention relates to a beam diverter unit for multiaxial investigation of samples in a microscope, allowing on the one hand the illumation and/or observation of the sample from various sides, and on the other hand observation of the sample at a certain angle to the illumination axis. Investigation of the sample occurs through an available microscope with the above-mentioned beam diverter unit, which is located between the microscope objective and the focal plane. The observation optical path (1) can be partially constructed in a manner symetrical to the illumination optical path (1) (indicated with dotted lines). The central beam (12) emanating from the illumination focal point (9) indicating the situation of the observation axis, and the marginal beams (13, 14) hit the beam diverter unit (8) in accordance with the invention and are reflected there. They are collimated by an appropriate distance between the beam diverter unit (8) and the focal plane (6) and an appropriate inclination angle α2 of the beam diverter unit from the microscope objective (5). The beams (12, 13, 14) pass through the exit aperture of the objective (5) at a reflexion angle β2 and reach a detector (30) with an upstream pinhole (20) via the lense and the optical system (25, 26). Without a beam diverter unit the beams (12, 13, 14) would intersect each other at a point (15) in the focal plane (6). This beam path is indicated by thin lines.