The aim of this diplom thesis was analyse differences in heat air drying between wood of spruce (Picea abies L.KARST) and fir (Abies alba Mill.). These both type of woods we dryed in heat air kiln in select mode on 60, 80 and 120° C. We are decide to select on drying the wood of spruce and fir because in practice have both type of wood are drying in the same mode of drying and we want comparase their characteristic. In diplom thesis we focus on analyse of moisture content, moisture gradient and covering, density, colour difference and distribution of temperature. In first chapter we describe wood of spruce and fir and preparation of material. In second chapter describes the measurement procedures in the tests used. The third chapter evaluates the results of experimental work with processed data in tables and graphs. The fourth chapter describes the discussion of the results of experimental measurements. In the end, our results are summarized.