The topic of this thesis is optimization of plasma cutting parameters for alloy steel enhancement. The theoretical part of the study provides a detailed description of the plasma cutting process, different variations of the process, and the key characteristics of each variation. It defines plasma as the fourth state of matter and outlines the main systems and their components involved. Various performance possibilities of plasma cutting technologies are described, with emphasis on their characteristics. At the end of the theoretical part, the most important characteristics of the type of steel used in the experiment are listed. In the experimental part of the research conducted at the Joining Techniques Laboratory at the University North, the plasma device Hypertherm Powermax30 AIR was used to cut 4 mm thick 25CrMo4 steel in its untreated state. Samples were cut at different speeds to optimize cutting speed regarding the quality of the cut. Various cutting speeds were applied for optimization, ranging from 70 to 90 cm/min, to assess the impact of cutting speed on the quality of the cut. After cutting, measurements of surface roughness were performed using a surface roughness measuring device, expressed by the parameter Ra [μm]. Based on these results, the average value of the Ra parameter [μm] was calculated. At the very end of the work, a conclusion was written about the obtained results of the experiment.