1. A presence data management method implemented by a plurality of devices connected by a network and a presence server storing referred information on the users of the devices that the users agreed to disclose, comprising the steps of: receiving an information reference request from the device of a user requesting information reference; detecting information processing functions of the device of the user as an information reference requester; processing the referred information on a referred user requested by the information reference requester depending on the detected information processing functions; and sending the processed referred information to the device of the information reference requester.