Abstract: In a method and apparatus for sifting particulate material in a cross current, the method and apparatus being of the type wherein all particles of the same size are propelled transversely at the same velocity of at least approximately 5 m/sec and with the same direction in a thin layer into a high velocity sifting gas current so as to preclude a determinative influence of gravity, the particles spread out into the current and after a time of flight of the order of magnitude of 1/100 second separated into two or more fractions by one or more knife edges disposed in a direction opposite to the material trajectories without previously rebounding from any wall, and the incoming sifting gas flow subdivided into at least two parts which are led off separately, improved separation characteristics are obtained by establishing an additional partial flow which is led off in a direction different from the influx direction of the sifting gas current, the partial flow having a momentum component in a direction opposite to