An apparatus for stacking signatures or the like includes a guide plate having a predetermined angle of inclination and a conveyor for successively loading signatures onto the upper end of the guide plate from the upper side of the latter. The foremost end of a stack of signatures which are being stacked on the guide plate is supported by a first support member which gradually lowers through a section from the signature loading position to an intermediary position, and is then supported by a second support member through a section from the intermediary position to an unloading position. The rearmost end of the stack of signatures is supported by a third support member through the entire section from the loading position to the unloading position. For this purpose, the first, second and third support members are repeatedly moved along the guide plate in relation to each other. Also disclosed are techniques accompanying the signature stacking technique, that is, means for pressing a signature at the loading section, means for forming a stack of signatures, auxiliary means for forming a stack of signatures and means for attaching a panel to each of the front and rear ends of a stack of signatures.