A gas flowmeter includes: device body (1) which accommodates a fluid to be measured; inlet pipe (4) through which the fluid to be measured flows into device body (1); and outlet pipe (5) through which the fluid to be measured flows out from device body (1) through connecting pipe (7). The gas flow meter also includes: ultrasonic flow rate measuring unit (9) which has a first end side connected to outlet pipe (5) and performs flow rate measurement of the fluid to be measured which flows in ultrasonic flow rate measuring unit (9); and connecting pipe (7) which is disposed between ultrasonic flow rate measuring unit (9) and outlet pipe (5), and is connected to outlet pipe (5). The gas flow meter further includes support member (10) which supports a second end side of ultrasonic flow rate measuring unit (9).
