FLOW METER DEVICE

A gas meter of the present invention includes a flow measuring section for measuring a flow value of a gas flowing through a fluid passage connected to a gas instrument at each specified time interval; a measurement flow memory for storing the measured flow value; and a fuel cell determiner section for determining that the instrument using a gas is a fuel cell, when a condition A and a condition B are satisfied, in which the condition A is such that a maximum value of determination target flow values is equal to or less than a second predetermined value, the determination target flow values being a predetermined number of flow values measured before and after a reference flow value which is equal to or greater than a first predetermined value and is closest to the first predetermined value, the determination target flow values being included in stored flow values, and the condition B is such that a difference value derived by subtracting from each of all of the determination target flow values, an average value found from the each determination target flow value and a predetermined number of measurement flow values measured before the each determination target flow value, is equal to or less than a third predetermined value.