PURPOSE: To prevent the stop of the operation of a device and to prevent the depression of service, by preparing mediums in plural sets of medium storage parts and switching a used set of medium storage parts to another set when it is detected that the residual quantity of mediums in the used set of medium storage parts is reduced to a prescribed quantity.

CONSTITUTION: Rolls 18W18' forming plural sets of medium forms are loaded to a carriage 28, and one set of medium forms is fed successively as a current set and is cut and discharged after data printing. A near end signal is transmitted by a near end sensor 24 and an end sensor 25a formed with a lever brought into contact with the roll 18 to light an alarm lamp 26, and a screw shaft 29 is driven by an end signal, and the carriage 28 is moved to the position of the roll 18', and a plunger magnet M is operated, and a driving roller R25 is engaged with a feed roller 18, and the leading edge of the roll 18' is pinched and is fed to a sprocket 9a. When all rolls are consumed (omitted in figure), the device is stopped to sound a buzzer. Thus, the operating efficiency of the device is improved, and the service for customers is improved.