PURPOSE: To shorten screen response time in an input/output device at the time of executing a slip registration processing.

CONSTITUTION: Slip data showing the plural slip names which are to be outputted by the input/output device 10 are inputted. Then, a slip registration device 20 receives slip data which are inputted from the input/output device 10 and to which there are plural output requests, registers a first output request slip name in a registration file 40, outputs slip data showing other remaining output request slip names and transmits registration completion information showing the registration completion of slip data to the input/output device 10. A slip registration device 30 receives slip data showing the other remaining output request slip names from the slip registration device 20 and sequentially registers slip data in the registration file 40.