To provide a topic extracting device for extracting topics with the usage of a network such as Internet, especially the topic extracting device capable of extracting hot topics from many document groups connected to the network.

A document is read from the document group 1, document analysis processing is executed and a keyword is read. Other documents including the keyword are retrieved among the document group 1. A virtual link is constructed between the related documents. With the usage of the newly constructed virtual link and the already constructed hyper link, the topics on the network are extracted based on the weighting and the related information added to the virtual link, and the topics are displayed to a user.