PURPOSE: To provide a printer which informs a host computer of printing state such as printing sequential order.

CONSTITUTION: CPU 10 stores printing sequential order in a buffer 20 together with information such as the name of a host computer and printing pages which is included in a printing command, if the command is received from host computers 30, 31. Next, information stored in the buffer 20 is sent to the host computers 30, 31. CPU 10, based on the printing sequential order as information stored in the buffer 20, prints print data entered from the host computers 30, 31, and changes the printing sequential order as information stored in the buffer 20, if the printing process is ended. In addition, the buffer 20 sends the updated information stored in the buffer 20 to the host computers 30, 31 which are on standby for information.