The diploma thesis deals with the determination of the dimensions of Picea abies dust, Fagus sylvatica and Populus tremula by laser dimensional analysis. Experimental samples of the individual dust particles were prepared by a manual belt sanding sanding grinder 120, to obtain the clean samples required for laboratory measurements. The choice of wood was selected by evaluating the more elaborate wood in our wood industry. In the process, a number of dust mixtures occur in the state of products, intermediates or waste which are of different dimensions. Particles with small dimensions are too dangerous because they can create explosive atmospheres at a certain concentration and then explode or explode explosively. The aim was to experimentally determine the particle size measurements using a Mastersizer 2000 laser analyzer to determine the dimensions of the individual wood dusts and their volume in the mixture. After the experimental part, we concluded that dust particles of the spruce (Picea abies) were the smallest. The measured values of all dust particles were low, therefore regular inspection and cleanliness of the technological areas of the wood production and the implementation of preventive measures against the explosion protection are necessary.