Paper presents experiments with processing parameters on additive manufacturing machine working with SLM method for stainless steel 316L. Most of the experiments which have been done before are on machines which are equipped with fiber optics lasers and these processing parameters cannot be used on machines which are equipped with CO2 lasers. Aim of research was to test processing parameter influence on printed material density and mechanical properties. Experiments were performed on Aurora Labs Titanium Pro machine which is equipped with two CO2 lasers with total power of 300 W. For processing parameters laser power was used at 300 W, laser travel speed was varied from 1500 mm/min to 2400 mm/min. Hatch distance was changed from 0.8 to 0.3 mm and layer thickness was changed from 30 µm to 50 µm. Specimens were polished and material density was evaluated by imaging analysis software and tests on tensile strength were performed.