This invention is to generate a press fitting force between the paper supply roller and the separation roller by attaching a weight to the paper supply shaft of the paper supply roller to feed sheets of paper and applying a load to the paper supply roller. The press fitting force of the paper supply roller generated by a load of the weight remains unchanged irrespective of secular change or wear of the paper supply roller or the separation roller and is kept in the same level as that at the initial stage, and the separation and conveying of sheets of paper by the paper supply roller and the separation roller can be carried out certainly for an extended period.