A monitoring center notifies emergency broadcast request information specifying its broadcast area to a prescribed emergency broadcast processing apparatus when any sensor detects an abnormality and determines that an emergency broadcast is needed. When acquiring the emergency broadcast request information transmitted from a plurality of monitoring centers, the processing apparatus grasps contents specified in the request information to notify information necessary for the emergency broadcast to a broadcast station covering an objective area. When a request instruction for the emergency broadcast is issued, the broadcast station arranges contents of emergency information in free areas in a broadcast format, arranges control information to start receivers in the objective area and also automatically select a channel at a defined position in the broadcast format to create an emergency broadcast signal and multiplexes it with a normal broadcast signal to broadcast it.