To easily execute the detection of abnormality and the restoration of an original state by detecting abnormality by a sensor and informing an information destination of the detected abnormality through a telephone installed in a target to be monitored.

When the occurrence of abnormality in a target to be monitored is detected, abnormality in individual information is stepwisely reported from a sensor 10 in accordance with the set state of contents to be informed of. Namely abnormal information from a signal sensor is reported to a specified information destination as individual information by a specified signal sort first of all. When unified judgement based on the detection of abnormal information from plural sensors is executed the specified information destination is informed of the occurrence of burglary by the specified signal sort. When an external notification device 11 is connected the abnormality is simultaneously notified to the outside of an automobile or the like to be the target to be monitored by the generation of a warning tone/lighting of a warning lamp.