An electronic mail having thereon an URL of a conference host peer machine for automatically taking part in a conference by clicking once is sent to a plurality of conferee peer machines. A conferee peer machine at a shortest time location is searched through communication tests from the conference host peer machine to distribute data. After the distribution of data, remaining conferee peer machines are informed that the data distributed conferee peer machine is a mirror of the remaining conferee peer machines, and a conferee peer machine at a shortest time location is searched through communication tests from the conference host peer machine and from the mirror to distribute data. The above processes are repeated until data distribution completes.