It is assumed that a presenter A makes an important statement at a scene 2 in a real-time conference. Participants B and C press a chapter insertion button at times t4 and t5 respectively (steps S1-1 and S1-2). A conference server turns back the time by a predetermined time from the times t4 and t5 (steps S2-1 and S2-2) and sets headings (manual insertion chapters) HCP2 and HCP3 at the turned-back times (t2 and t3). Alternatively, the conference server determines the time separator just before the time (namely, CP4) and sets a heading HCP1 at the time (S4). Accordingly, the heading is set before the scene 2 where the presenter A makes an important statement.