To provide a paper sheet processor for improving the processing efficiency of paper sheets by reducing the movable distance of extraction backup by setting the initial position of extraction backup according to the number of sheets of a collation unit.

A transport controller 65 sets extraction backup 101 at the lowermost part of an extraction conveyance device 11 when the number of the sheets of the collation unit of the paper sheets is 1,000, and sets the extraction backup 101 a little below the uppermost part of the extraction conveyance device 11 when the number of the sheets of the collation unit is 100. A staff places a paper sheet bunch P on the extraction backup 101, and depresses a supply start button 34, so that the paper sheets can be extracted by an extraction roller 11a, and transferred to a conveyance section device 13. When the extraction ends, the extraction backup 101 is let out to the same height as that of the initialization position by a link mechanism 102.