When a management PC (as an address information display device in an address information display system) displays IPv6 addresses that have been assigned to a device in the system, the addresses may be displayed in a pull-down menu, for example. The display order in the pull-down menu may be determined according to a priority order which can be set arbitrarily by the user. Further, addresses judged to be important (according to settings by the user) may be displayed using a bold font, local addresses are displayed in italic, addresses close to the expiration of term of validity may be grayed out) and invalid addresses (addresses already expired) may be grayed out with strikethroughs. As a result, an address information display system may be realized that is capable of displaying addresses assigned to a device in a style easy for the user to understand.