The main goal of the diploma thesis is to increase the efficiency of CNC centers. This means increasing the machining speed and maintaining the machining quality.In the first chapter, the work deals with the basic requirements of CNC standing and basicTheory on the principle of CNC machines.The second chapter deals with a theoretical analysis of the milling process. It characterizes the milling process and characterizes the individual types of milling.In the following third chapter we define quality, we deal with types of inequalities that affect quality and characterize the process of measuring surface roughness.In the fourth chapter we deal with the influence of technical and technological parameters on quality and explain the process of theoretical calculation of surface roughness.The fifth chapter contains a work goal. There is a methodology in the sixth and in the seventh chapter we find the results themselves.