Described is a cleaning unit for a device for harvesting long agricultural products, such as grass, straw, pulses, biomass products and the like, of the type that can be pulled by a pulling vehicle along an advancing axis and provided with pick-up means (102) for harvesting said products and with unloading means (106) located operatively downstream of the pick-up means (102), forming a supporting surface (B) for the agricultural products harvested and mobile transversally to said advancing axis along a predetermined axis of movement (A) for releasing the agricultural products to the sides of said pulling vehicle, wherein the cleaning unit comprises a wheel (2) comprising a peripheral annular surface (3) and rotatable about its own axis of rotation (C) and joining means (5) designed to connect said wheel (2) to said harvesting device (100) in such a way that said axis of rotation (C) is transversal to said axis of movement (A) and wherein said peripheral annular surface (3) is positioned at a predetermined height in such a way as to form, between the peripheral annular surface (3) and the supporting surface (B), an agricultural product feed section (4).
