PURPOSE: To ensure a report when abnormality occurs, and to promptly and surely takes measures to an abnormal condition by transmitting and receiving information in an interactive form on a voice basis between a supervisory device side and a report objective person.

CONSTITUTION: A voice responding device 5 decodes response information from the report objective person, converts it into a corresponding sentence or a symbol, a computer 1 discriminates the nearest information based on the decoded information, and delivers it to the voice responding device 5. Further the transmitting information converted into a sound signal is resent by a line controller 4. The resent information is for example, made into the voice information of the operating condition or measured value of related equipment for the transmission request of the abnormal condition. Thus, the report by means of a public line between a supervisory device 2 side and report objective persons 41 to 4n is attained by the report and confirmation on the voice bases, and by the transmission/reception of the necessary information, and the report processing in the interactive form is attained when the abnormality has occurred, and the sure report is promptly issued.