A gas instrument determiner section (12) included in a flow meter device (10A) determines a kind of a gas instrument (20) in use by utilizing a flow pattern in which a range of increase/decrease in a gas flow is within a flow zone set in a fuel cell (21) as a flow pattern which is a pattern of a gas flow which changes over time when the fuel cell (21) is included in the gas instrument (20) in use. This makes it possible to accurately determine whether or not the gas instrument in use is the fuel cell while effectively suppressing unnecessary gas consumption.