A paper sheet handling machine according to the present invention includes: an imaging unit configured to take an image of a paper sheet and generate a paper sheet image; an identification unit configured to identify a character of each digit position included in a serial number, from a serial number region of the paper sheet image; an output unit configured to output the image of a part corresponding to the serial number region of the paper sheet image, when there is a digit position whose character therein cannot be identified by the identification unit; a display unit configured to display each character identified by the identification unit as well as the image outputted from the output unit; and an input unit configured to accept input of each character corresponding to the digit position whose character therein cannot be identified by the identification unit.