This diploma thesis deals with the issue of the influence of selected technical-technological and tool factors in the plane milling of thermally modified wood on the morphology of surface formation of foreign wood Meranti. The theoretical part of the work describes foreign wood Meranti, heat-treated wood, milling, surface roughness and surface roughness measurement. The next part deals with the methodology of work and describes the preparation of samples and a description of the equipment used. The experimental part focuses on the evaluation of the effects of technological factors (cutting and sliding speed), tool effects (angular geometry) and material (natural, heat treated: 160 °C, 180 °C, 200 °C, 220 °C) on the roughness of the machined surface. The following chapters point to the evaluation of the results, which are shown in tables and graphs prepared in the program STATISTICA 12. The main goal of the work was to find the parameter (technological or tool) that most affects the quality of treated surface of heat-modified Meranti wood for planar milling. Contribution to science and practice, the conclusion is the last part.