Elimination of light additives in the dust form from seed material is a significant problem of post-harvest seed processing since leakage of pneumatic machines systems for cleaning seeds enables dust to get outside which deteriorates the ecological condition of the surroundings. The article presents a developed machine for initial seeds cleaning, which divides air waste into fractions of seed and waste additives and purifies the air which circulates in the closed pneumatic system from silt additives, which deposit in the depositions chamber with difficulties. Models of regression of the functioning process of the developed machine were presented. Rational parameters of the inlet window of a dust collector (Δ = 0.03 m, δż = 0.012 m, Sż = 0.16 м, βP = 155°) and the edge of the partition wall of compartments of light fractions deposition (х = 0.21...0.23 m and у = 0.160...0.175 m) were determined. The developed machine improves the ecological condition of the environment concerning post-harvest seed processing systems.