Described is an apparatus for distributing particulate material on a drum or conveyor (103 movable along a respective operating direction (A). The apparatus comprises at least: a tank (211) containing particulate material (SAP1) and equipped with feed means (212) for feeding the particulate material (SAP1) and distribution means (214) located downstream of the tank (211) to receive the particulate material (SAP1) from the feed means (212) and configured to distribute the particulate material (SAP1) on the drum or conveyor (103). The distribution means (214) comprise at least a diffuser element (215) and a vibrating device (220) configured to shake the diffuser element (215), where the diffuser element (215) extends with its sliding plane (P) along its axis (D) between an infeed portion (215a) of it, facing the feed means (212) to receive a preset flow quantity "Q" of particulate material (SAP1), and an outfeed portion (215b) of it, of predetermined width (L), which can be positioned to face the drum or conveyor (103). The diffuser element (215) is also equipped, at an intermediate position, with at least one transversal partition (216) at a predetermined distance from the sliding plane (P) in order to form a neck which acts in combination with a vibration imparted by the vibrating device (220) in such a way as to distribute the particulate material (SAP1) along the predetermined width.Linvention concerne un appareil de distribution de matière particulaire sur un tambour ou sur un transporteur (103) mobile selon une direction fonctionnelle respective (A). Lappareil comprend au moins : un réservoir (211) contenant une matière particulaire (SAP1) et pourvu dun moyen dacheminement (212) pour acheminer la matière particulaire (SAP1) un moyen de distribution (214) situé en aval du réservoir (211) pour recevoir la matière particulaire (SAP1) provenant du moyen dacheminement (212) et configuré pour distribuer la matière particulaire (SAP1) sur le tambour ou sur le transpor
