A device for feeding sheets into an insertion device before a digital printer characterised in that it comprises: - a base with actuation, with an acetal band or metal rollers, wherein a stack of sheets, stacked vertically and ordered among each other, is positioned anchored on a lifting system which in turn comprises: - crossbars and pillars which are positioned by means of guides, - a motorised lifting mechanism, - an extraction mechanism for the last board, - an insertion system which in turn comprises: - a pressure system through an advance mechanism which enables the stack of sheets structured vertically and ordered among each other to be separated into groups with a known size, - a rotation system, for the transfer, with the capacity to rotate the stack/s an angle to be selected between 90 degrees, 180 degrees and 270 degrees, - a positioning stop with the capacity to correctly position the stack/s, which is the process before rotating, connected to an advance and reverse mechanism, in the direction longitudinal to the digital printer, - a squaring and scaling station, able to create a loading and accumulating hopper if necessary, wherein the stack/s arrives from the previous process, and wherein it is squared and scaled by means of mechanisms, front stops and lateral stops, and - a telescopically-adjustable transportation system, with the capacity to move the previously-scaled sheets until the insertion device is fed; such that: - the lifting system has the capacity to vertically move a stack of sheets, - the insertion system has the capacity to provide ordered stack groups from the original stack. - a base with actuation, with an acetal band or metal rollers, wherein a stack of sheets, stacked vertically and ordered among each other, is positioned anchored on a lifting system which in turn comprises: - crossbars and pillars which are positioned by means of guides, - a motorised lifting mechanism, - an extraction mechanism for the last board, - crossbars and pillars which are positioned by means of guides, - a motorised lifting mechanism, - an extraction mechanism for the last board, - an insertion system which in turn comprises: - a pressure system through an advance mechanism which enables the stack of sheets structured vertically and ordered among each other to be separated into groups with a known size, - a pressure system through an advance mechanism which enables the stack of sheets structured vertically and ordered among each other to be separated into groups with a known size, - a rotation system, for the transfer, with the capacity to rotate the stack/s an angle to be selected between 90 degrees, 180 degrees and 270 degrees, - a positioning stop with the capacity to correctly position the stack/s, which is the process before rotating, connected to an advance and reverse mechanism, in the direction longitudinal to the digital printer, - a squaring and scaling station, able to create a loading and accumulating hopper if necessary, wherein the stack/s arrives from the previous process, and wherein it is squared and scaled by means of mechanisms, front stops and lateral stops, and - a telescopically-adjustable transportation system, with the capacity to move the previously-scaled sheets until the insertion device is fed; such that: - the lifting system has the capacity to vertically move a stack of sheets, - the insertion system has the capacity to provide ordered stack groups from the original stack. - the lifting system has the capacity to vertically move a stack of sheets, - the insertion system has the capacity to provide ordered stack groups from the original stack.