PURPOSE: To eliminate the residued freight at freight unloading time and the dropped freight from a freight truck at freight unloading plate returning time by a device for unloading the freight in the freight body of the truck upon longitudinal movements of the freight unloading plate.

CONSTITUTION: In a device for unloading freights in the freight body 2 of a freight truck upon longitudinal movements of a freight unloading plate 8 provided in the freight body 2 carried on a truck body frame 1 are formed guide grooves 7 longitudinally extended along both side walls 3 of the freight body 2. Supporting rollers 10 are journaled at a shaft 11 to the supporting member 9 of the plate 8, and are rotatably engaged with the groves 7. The centroid G of the plate 8 is disposed at the position forward from the body 2 from the shaft 11 in such a manner that, when the plate 8 is in free state, it is spaced from the floor surface 13 of the body 2 at the lower edge thereof and that, when cylinders 14 are extended at its rods at both sides of the body 2, the plate 8 is slidably in contact with the floor surface 13 at the lower edge thereof.