In an image search server which is connected to databases storing images and to image display terminals and searches the databases in response to a request from any of the image display terminals for displaying a search result on the terminal, responsiveness of an image search is improved while a search of all the databases is possible if necessary. An image search server stores images fetched from databases of image archiving apparatuses in storing means thereof, such as a hard disc. For each of the image display terminals, the image search server has setting defining whether the databases and the storing means or only the storing means are searched, and selects where to search according to the setting.