To provide a printing system and a print instruction device and a printer for preventing the coexistence of the printed matter of a user himself and the printed matters of the others in the case of performing printing divided several times.

A user A transmits an accumulation instruction to a printer 20 as the destination of printing from a host terminal 10. The user A is supposed to instruct printing several times following this instruction. Also, not only this printing instruction but also print data relating to the instruction are supposed to be successively transmitted to the printer 20. In the case of accumulative printing, printing is not immediately started, and the execution of printing is held. After ending the printing instruction, the user transmits an ejection instruction to the printer 20. In accordance with this instruction, the printer 20 continuously executes printing corresponding to the print data relating to the printing instruction made several times from the user. That is, the instructed printing is continuously executed several times.