PURPOSE: To provide a double feeding and jamming detection device for automatic paper sheet feeding device capable of detecting double feeding surely and also detecting jamming at the same time as double feeding, even when paper sheets of which transmissivity varies and document are fed and also even when two sheets of paper overlapped completely are fed.

CONSTITUTION: The number of paper sheets n delivered from a hopper and the number of paper sheets m entering a stacker are monitored, variations in weight ΔX and ΔY of the hopper and the stacker during that while are obtained, a difference (ΔX-ΔY) of them is compared with (n-m) a. Here, when (ΔX-ΔY)-(n-m) a is negative, feeding is judged to be double feeding and, when it is positive, it is judged to be jamming.