The dissertation thesis deals with the experimental examination of the temperature influence of heat treated oak wood in terms of quality of the machined surface. As well as analysis of the impact of monitored independent parameters; vc - cutting speed, vf - feed rate, material, angular geometry of the tool, on dependent parameters representing surface treatment quality (Ra - mean arithmetic roughness, Rz - maximum roughness, Wa - waviness profile) in flat milling of thermally modified oak wood (T = 180° C, T = 200° C, T = 220° C), and their comparison with native wood. The roughness measurement was carried out by a contact and non-contact method. The results of both measurements were compared with each other. Based on the mathematical and statistical analysis, the impact of individual parameters was optimized to achieve the surface finish quality at the final product level. Based on experimental measurements, the effect of the observed factors on surface quality was determined in this order: used type of cutting tool, thermal modification, cutting speed vc, feed speed vf, angle γ.