Abstract: A recirculating document feeder adapted to transport each document sheet from a stack of such sheets to an exposure position through a circulation path. After printing, the sheets are returned to a sheet support portion with the front ends thereof brought to a specified position irrespective of the size of the sheets so as to be re-feedable properly. For this purpose, a sheet rear end guide for delivering the sheet to the support portion from a rear portion thereof is made movable longitudinally of the feeder to an adjusted position. A return guide is provided under the support portion toward its rear end for returning the sheet to the support portion through one of sheet delivery openings formed in the bottom plate of the support portion.