Abstract. A Tandem Scanning Reflected Light Microscope (TSRLM) with computer image analyser and with a structure quantimeter (hardware, software and rotary microtome) are presented and compared to other microscopic methods with respect to new possibilities in visualisation of biological material. Scanning optical microscopes are the most recent constructions in optical microscopy. They offer the rejection of out-of-focus noise and higher contrast than the conventional imaging. The only allowed to reach a detector is the light emitted from the objective focal plane. This cuts off any out-of-focus image blurring. A short history of confocal microscopy from Marvin Minsky to Tandem Scanning Reflected Light Microscope (TSRLM) and Confocal Laser Scanning Microscope (CLSM) has been presented. The use of scan­ning optical and electron microscope method for the investigation of biological materials is estimated and compared.