A gas meter and a center device, including an analyzer, analyze a cause of an abnormality determination. The center device requests analysis-use data necessary to analyze the cause of the abnormality determination from the gas meter, through a communication by a center communication unit, based on the abnormality type data received from the gas meter. The gas meter transmits the analysis-use data requested by the center device to the center device by a meter communication unit, and the analyzer of the center device determines the cause of the abnormality determination based on the received analysis-use data.