The invention relates to a device for feeding products in sheets into an insertion device before a digital printer, including a lifting system for a stack of laminar elements, which in turn includes an extraction mechanism for the last board, an insertion system with an advance mechanism, a rotation system for the stack(s), a positioning stop, connected to an advance and reverse mechanism, a squaring and scaling station, able to create a loading and accumulating hopper, and a telescopically-adjustable transportation system, with the capacity to move the previously-scaled sheets until the insertion device is fed.