A conference system, capable of reliably managing a connection state of a discussion unit and a control unit and continuously acquiring information from the discussion unit when a connection abnormality occurs, is provided.A conference system S includes a control unit 1 and a discussion unit 2, a running packet is repeatedly transmitted and received between both units, the running packet includes a counter flag, the control unit includes a CU communication portion 11, a CU storage portion 13, and a CU control portion 16, the discussion unit includes a DU control portion 26, the DU control portion increments the count value of the counter flag, and each time the running packet is received from the discussion unit, the CU control portion compares a count value stored in the CU storage portion and the count value of the counter flag included in the running packet received from the discussion unit.