A communication information registering unit (11) acquires communication information that contains a sender, a receiver, and a sending time of information communicated between users that are communicating, and stores the communication information in a storage unit (12). A response time calculation unit (13) finds response time of the users from the communication information. A threshold value setting unit (14) finds a threshold value for determining the statuses of the users from distribution of frequencies of the response time. A current status determination unit (15) determines the status of a counterpart user from the response time by using the threshold value. A notification unit (16) notifies a user of the current status of its counterpart user.