PURPOSE: To transfer only finished articles to the succeeding process with no carton under folding process remaining at the time of work completion.

CONSTITUTION: A carton A carries boxlike contents B with U-shaped body windings in and passes over a swing plate 2a of a transfer pocket C that is on standby at the upmost-stream side in the transfer direction, causing a folding- down piece 7 to be brought in action to fold upside body flaps A2 of the carton A down. After that, the swing plate 2a is raised to fold downside body flaps A1 of the carton A up and lay them on the outsides of the upside body flaps A2, thus body folding of the carton A is completed. Then, the transfer pockets C are simultaneously transferred by intermittent actions of endless flexible members 4 and 5. Thereby, side flaps of the carton A after body folding is completed are folded in turn by a folding piece 8 to finish case packing.