PROBLEM TO BE SOLVED: To prevent a potentiometer of a layer thickness sensor from getting obstructive or from being damaged by a contact with an oscillating sorter, when attaching/detaching the oscillating sorter.SOLUTION: A threshing part 3 comprises: an oscillating sorter 20 for sorting, while transferring processing materials from a threshing chamber 14, sieved through a receiving net 18 and a layer thickness sensor 34 for detecting the layer thickness of the processing materials being transferred on the oscillating sorter 20. The layer thickness sensor 34 includes: a detection body 35 freely turning according to the layer thickness of the processing materials and a potentiometer 36 for detecting a turning position of the detection body 35. When the layer thickness sensor 34 is fitted to a receiving net support frame 32 disposed above the oscillating sorter 20, the potentiometer 36 is disposed laterally to the receiving net support frame 32 and on the upper side of the lower end of the receiving net support frame 32, so that the freely turning detection body 35 is suspended downward from the lower end of the receiving net support frame 32.
