Abstract: In treating nuts which are supplied by way of transport means and which are held between two conveyor belts, a groove of uniform depth is milled into the shell of the nut by means of overlapping milling discs, which groove permits the shell of the nut to be broken open by a subsequent splitting means.On the transport means, the nuts are separated and aligned by vibration and the configuration of the guide tracks. A spiral conveyor with a baffle is also provided for this purpose.The conveyor belts are adapted to the different thicknesses of the nuts by means of vertically adjustable rollers.The depth of the groove which is less than the thickness of the shell of the nut is restricted by toothed rings on the milling discs and annular shoulders which are arranged at a displaced position relative thereto radially with respect to the axis of rotation.