An apparatus for threshing legumes has a frame, which is movable over a ground surface. A drum, which is rotatable about its at least substantially horizontally oriented axis of rotation, is mounted on the frame and has a drum surface provided with one or more openings. A main threshing element is disposed within the drum and is rotatable about its longitudinal axis, which extends at least substantially parallel to the axis of rotation of the drum. At least one auxiliary threshing element is disposed within the drum and is rotatable about its longitudinal axis, which extends at least substantially parallel to the axis of rotation of the drum. An additional conveying member is disposed within the drum for conveying the legumes to be threshed through the drum. The apparatus has a detection device that measures an angle of inclination of the apparatus with respect to the horizontal and a control device that control the additional conveying member on the basis of the measured angle of inclination.