Abstract: Automatic service apparatus for fast printers (10) including a store (12) containing reams of papers to be printed, a mechanical arm (16), equipped with pliers (24), movable among a plurality of boxes (14) for drawing reams from the store (12), unpacking and aligning sheets from the ream, depositing one of the reams into a sheet feeding seat of a printer (10), drawing groups of sheets from the output of the printer (10) and transferring the groups to an after-treatment station (60). The pliers can be provided with a static device for aligning the reams.