Apparatus for the separation of agricultural or vegetable product, with a fixed structure having two parallel horizontal side members, a plurality of cutting modules equipped with a common rotating shaft having a plurality of rotating blades in fixed position along its length, said shafts being parallel to each other and mounted above conveying means suitable to carry the products placed thereon toward said rotating blades, a plurality of positioning ramps mounted in a position corresponding to a respective rotating blade and having a shape elongated in the direction of movement of said conveying means and almost flattened and oriented vertically, the elongate upper edge of which is oriented downward toward said conveying means with an inclination such that the height of said edges increases in the feeding direction of the conveying means, so that the clusters of products placed on said conveying means are carried toward said ramps, the respective upper edge of which determines the point of intersection of the respective blade with the stems of each cluster carried under the blade, wherein: - said conveying means include a table formed by a plurality of parallel grooves substantially orthogonal to said rotating shafts and reciprocally separated by respective raised portions; - said table moves in a direction parallel to said grooves; - said ramps are arranged in positions corresponding to said respective grooves, - and the projection of each of said ramps with respect to one of said groove is aligned with the same groove. According to the invention, manoeuvring means are arranged, designed to rotate an auxiliary shaft around its centre of rotation so that said upper edges and the tips of the respective ramps are rotated so as to cause the rotational lifting of said ramps by a predetermined angle.