When a setting relating to the print quality of a printer 3 is changed (T601), sending of ssdp:byebye to PCs 2 (T603) and time measurement by a timer 37 (T605) are executed. Then, after the elapse of 30 seconds from the start of time measurement by the timer 37, ssdp:alive is sent to the PCs 2 (T615). Even if a paper size related setting change (T607) or multiple page printing (condensed printing) setting change (T609) is made during this 30-second interval, ssdp:alive is not sent to the PCs 2 for those changes executed during the 30-second interval.