To provide an automatic parameter setting system for a gas meter capable of setting an accurate parameter on the gas meter inexpensively in a short time, and the gas meter.

This system is equipped with the gas meter 10 arranged in a gas passage 21 and having a flow sensor 33 for detecting the gas flow rate, a flow control device 12 for controlling the flow rate of the gas supplied into the gas passage 21 of the gas meter 10, a standard flowmeter 13 for measuring the flow rate of the gas supplied from the flow control device into the gas passage of the gas meter, and a setting device 14 for setting the parameter so that the gas flow rate metered by the gas meter approaches the gas flow rate measured by the standard flowmeter and transmitting the set parameter to the gas meter. The gas meter has a memory 32 for storing the parameter from the setting device, and the gas flow rate detected by the flow sensor is corrected following the parameter stored in the memory, to thereby meter the gas flow rate.