PURPOSE: To permit a highly efficient packaging operation, by temporarily dwelling an article under packaging operation in a dwelling device attachable to an automatic packaging line, in the case of changes in the shape and kind thereof.

CONSTITUTION: A work detector 3 measures the shape of a work 4 passing therethrough and sends its result to a control apparatus 1, which judges whether the work is a proper article for packaging and, if so, gives an instruction to a cross conveyor 5 to convey the work 4 in the direction A and, if not, gives an instruction to the cross conveyor 5 to convey the work 4 in the direction B and also to a dwelling device 7 to store the work 4 in a predetermined position and, at the same time, updates its inventory record in the dwelling device 7 of the control apparatus. A cross conveyor 6 receives the work 4 normally from the direction C and conveys the same in the direction D. Upon later rearrangement of an automatic packaging line 8 responding to changes in the work 4 in the dwelling device 7, however, it receives the work 4 from the direction E and conveys the same in the direction D.