To solve a problem wherein processing time increases when rotational speed of a page turning roller is made low in order to prevent turning-over of two sheets.

A page where turning-over of two sheets is apt to occur in turning pages of a bankbook is specified, and the rotational speed of the page turning roller is made low only when turning the page. In order to specify the page where turning-over of two sheets is apt to occur, information on the number of middle sheets of the bankbook is given to a magnetic stripe or a page bar code of the bankbook. The information on the number of middle sheets recorded on the magnetic stripe or the page bar code is read when the bankbook is inserted. If it is the page where turning-up of two sheets is apt to occur, specified in accordance with the number of middle sheets when turning the page, the rotational speed of the page turning roller is made low to suppress the occurrence of turning-over of two sheets.