CO ALARM SYSTEM

PROBLEM TO BE SOLVED: To provide a CO alarm system which ensures safety of a user and reduces inconveniences experienced in daily life.SOLUTION: A CO alarm system 1 comprises a gas meter 2 and a CO alarm unit 3 which is communicably linked with the gas meter and which detects CO concentration and outputs a CO detection signal to the gas meter in accordance with the detection result. The gas meter includes flow rate detection means for detecting flow rates of gas supplied to each gas appliance, gas appliance identification means for identifying gas appliances in use among a plurality of gas appliances on the basis of the gas flow rates detected by the flow rate detection means, and transmission means for transmitting gas appliance information of gas appliances in use identified by the gas appliance identification means. The CO alarm unit includes reception means for receiving the gas appliance information transmitted by the transmission means, and first notification means for generating a message corresponding to the gas appliance information received by the reception means.