The invention concerns an automatic device for turning the pages of a bound document comprising a support (11) whereon is arranged the document, means (14) for separating by suction one page from the other pages to be turned and for turning the separated pate to bring it on a pile of turned pages. The support (11) consists of two mobile trays (16) mutually linked by a rod (17), each tray consisting of a box (26) whereof the upper side is provided with small holes (27), co-operating with the suction intake orifices (28). The means (14) for separating the document pages consist of suction means (34), displaced by the combination of a vertical movement and a horizontal movement, consisting of a perforated recessed element (36) provided with a diaphragm (37). Said perforated element (36) is provided with holes (38) and the diaphragm (37) comprises two mobile parts for orienting the direction of the suction flow and modify its flow rate and its speed. Said suction means (34) also comprise mobile closure means (44) for longitudinally delimiting the suction surface. The means (14) for turning a page of the document comprise two mobile transparent plates (30) arranged in parallel planes. Control means (13) enable to measure the dimensions of the document and the number of pages turned.