An insect sorting device, machine, and use thereof, which improves sorting efficacy by prompting the insects to cling onto the belt, comprising a belt conveyor (2) having an upper surface (5) and a lower surface (6) formed by the belt (3) of the conveyor (2). When the belt (3) is turned over to pass onto the lower surface (6) of the conveyor (2) all or some of the insects of a mixture remain attached to the belt (3) while the rest of the mixture falls by gravity. The upper surface (5) of the conveyor (2) being substantially flat and horizontal over a majority of its length between the first end (7) and the second end (8), it comprises an end portion (14), adjacent the second end (8), having a downward inclination, comprised between 20° and 90° relative to the rest of the upper surface (5) of the conveyor (2).