SPO sieve separator of preliminary cleaning is intended for separating grain from large impurities such as: straw, spicate, mineral, etc., the size of which exceeds size of grain. The working principle of the sieve separator of preliminary cleaning SPO based on the reciprocating movement of sieves, both in horizontal and in vertical direction, leading to more efficient passage of grain through the sieve. For a more uniform and stable passage of the grain over the sieve moving scrapers, which distribute the grain over the screen for a more effective use of it and not allow it to go to waste. After the scraper is a brush that sweeps away the major impurity, not come through the sieve. Separator pre-treatment used at the enterprises engaged in post-harvest handling of grain. And used as part of zernotok, in samopodgotovka departments of the elevators, but is also part of the complete equipment to remodel and newly constructed. and granaries, together with such equipment as separators, BTSS, etc.