The TOA TS-910 Series conference system permits both its infrared wireless system unit and wired system unit via CAT-5 LAN cable connections to be used in combination. The wired chairman and delegate units (collectively referred to as “Conference units”) are connected to the central unit via the wired expansion unit and bridge unit. The infrared conference units provide wireless communication via the infrared transmitter/receiver unit connected to the central unit. Since wiring to the individual conference units is not required, they can be easily installed in freely versatile configurations. The Central unit is used to perform system function settings and status display.