A paper sheet receiving/dispensing apparatus includes strip films at least one of which is affixed, on at least one of front and back sides, with marks at intervals of a predetermined pattern in a predetermined shape and in a color different from a color of the strip films, a detection sensor for detecting the marks, and a storage device for storing a table that indicates an association between a roll outer diameter of the strip films wound around a winding drum and driving pulses of a stepping motor. The apparatus calculates the roll outer diameter based on the number of rotations of the winding drum, which is calculated based on detection pulses of the marks, and thicknesses of the strip films and a paper sheet, and controls rotations of the motor with driving pulses read from the table.