A drive device is provided for a screening body of a screening machine, in particular for mineral materials for crushing, such as oil sand, with a drive motor, a synchronous transmission gear which is operatively connected thereto and has at least two output shafts which rotate in pairs in antiphase at the same rotation speed with respect to one another. The drive motor and the synchronous transmission gear are mounted in a stationary manner, separately from the screening body, at the side alongside the screening body, and do not oscillate therewith. Each output shaft has a single associated horizontal shaft which has unbalance elements, and which is connected to the output shaft by means of a rotationally rigid universally jointed shaft and is arranged with its axis parallel to the adjacent shaft and transversely with respect to the conveying direction of the screening body. The unbalance elements are arranged in the horizontal direction between the side walls of the screening body, the shaft is supported by bearing elements on a cross member which is connected to the side walls, the unbalance elements are arranged exclusively directly on the shafts, the bearing elements are arranged exclusively on the shafts in the axial direction of the shafts between the unbalance elements, and the bearing elements are supported on a cross member which is connected to the side walls.