The invention relates to a manipulation device for loading and unloading a shelf, in particular for a processing center, having at least one lift truck including a telescopic extension, the telescopic extension having at least one first telescoping part and at least one second telescoping part, and the first telescoping part being connected to the lift truck and the second telescoping part being connected to the first telescoping part so it is displaceable in an essentially horizontal displacement direction. To reduce the manufacturing expenditure, it is provided that the lift truck has at least one first linear roller bearing unit and at least one support roll, spaced apart from the first linear roller bearing unit in the displacement direction, in the area of sides parallel to the displacement direction, and each first telescoping part has at least one first profiled rail situated parallel to the displacement direction, each first linear roller bearing unit being guided in a first profiled rail, and the first telescoping parts being supported by the support rolls of the lift truck.