To provide a collecting device capable of preventing dropped packaging bags from getting caught in the device and to be piled in a correct posture at a correct position in order.

The collecting device consists of a sorting mechanism for guiding packaging bags alternately to the right and left, rotor blade mechanisms 210 and 211 for alternately receiving the sorted bags for guiding them into a horizontal posture, first shutter mechanisms 220 and 221 for collecting one to three bags in the horizontal posture, second shutter mechanisms 230 and 231 for collecting until the predetermined number of bags are reached, and a belt conveyer 240. The sorting mechanism consists of a sorting part for guiding the packaging bags transferred from a packaging machine alternately to the right and left and two right and left pockets for once holding the guided packaging bags respectively.