Abstract: A rotary microtome (1) for producing thin sections for histology is used for specimens (6) of different sizes. To maintain optimized cutting conditions, an adaptation to different specimen sizes is required without incurring disadvantages in terms of operation. An adjustment possibility is provided for the length of the vertical cutting movement (10). However, the moment that is generated by the vertical carriage (7) and that acts on the drive shaft (12) then changes. To maintain balanced moments of the drive movement, the counterweight has to be accordingly adapted by an adjustment weight (31). For this purpose, means are provided which, in an ergonomic and effective manner, permit the adjustment of the cutting stroke and also the necessary adaptation of the counterweights in one operation step.