To enable performing continuous operation over a long time without frequently stopping operation and further, to enable surely and separately recovering broken pieces of bags and valuable waste.

This device is provided with a belt conveyor 1 for conveying broken pieces of bags B and valuable waste P forward and making the waste P fall at the termination of a conveying route 1A and a waste recovering part 2 for recovering the waste P that has fallen from the termination of the conveying route 1A. Above the conveyor 1, an endless mesh belt 5 is arranged which is hung on front and rear belt wheels 3, 4 positioned in the front and rear parts from the termination of the conveying route 1A. The belt 5 moves forward in a lower belt movement route 5A. In the range form the termination part of the conveying route 1A to a part in front of the waste recovering part 2, a sucking means 7 for sucking the broken pieces of bags B on the back surface of the belt 5 of the lower belt movement route 5A is provided. In front of the waste recovering part 2 and below the endless mesh belt 5, a bag broken pieces recovering part 8 for recovering the broken pieces of bags B that fell by applying no suction force of the sucking means 7.