Analysis of the load under which the milling tool is at periodic circular cutting is shown. The research was performed in order to define the specific cutting force representing the basic technological parameter. The research includes the analysis of the influence of 2 material variables - the change of the direction of cutting and moisture content of the used material, and the influence of the feed speed as the basic technological variable. The tested samples, with different moisture contents, were made of beech wood (Fagus Silvatica). The system for measuring the parallel and the normal components of the cutting force on the moving test model was planned and made out. The feed speed of the test sample was constant during the cutting. The specific cutting force was increasing potentially along with the increasing depth and the angle of the cutting. In both cases the regressive coefficients reached 0.99 of value. The specific cutting force was almost identical at moisture contents of 8.2 and 18 %, while at 12 % the increase in value was traced. The feed speed did not influence the specific cutting force but it influenced the size of the parallel and the normal components of the cutting force.