In a full text search retrieval device connected to a plurality of user terminals, a received retrieval condition and terminal device information are stored in a trailing character buffer. If it is determined that a preceding retrieving process is not being performed, then a retrieval pattern variable table and a retrieval request expression variable table are generated. According to the retrieval request expression variable table, a database of the data to be searched is searched to extract a retrieval result matching the retrieval condition transmitted from each of the terminal devices, and the extracted retrieval result is transmitted to each of the plurality of terminal devices. Thus, although retrieval requests are continuously transmitted from respective users, a retrieval result can be returned to each user terminal in the same response time as in the case where a user terminal corresponds to a retrieval device.