A de-stoner machine separates stones and heavy impurities from grains by using a combination of air airflow and a vibrating, tilted mesh screen. As grain enters the machine, an upward air current lifts the lighter grain particles slightly above the screen surface and floats them smoothly downward toward the grain discharge outlet. Meanwhile, the heavier stones and debris remain on the mesh bed and, driven by the upward shaking movement of the screen, travel in the opposite direction toward the top end of the deck to be collected separately. This dual action of gravity, vibration, and air pressure ensures efficient, continuous cleaning without damaging the grain.