To provide an alarm system capable of performing alarming at a more appropriate timing.

The alarm system 1 includes a gas meter 40. The gas meter 40 includes: a gas use status determination unit for determining a gas appliance 10 used; and an alarm operation execution unit 43f for executing an alarm operation when a use status of the gas appliance 10 determined by the gas use status determination unit meets a predetermined condition. Thus, through determination of a gas appliance 10 used and execution of the alarm operation based on the use status of the gas appliance 10 used, an abnormality can be determined in more detail, and alarming can be executed at a more appropriate timing.