FLOWMETER

PROBLEM TO BE SOLVED: To provide a flowmeter that can correctly measure both a large flow rate and a small flow rate and can be made compact. SOLUTION: A large flow rate measurement part 1 for measuring a large flow rate of not smaller than a predetermined flow rate and a small flow rate measurement part 2 for measuring a small flow rate of not larger than a predetermined flow rate are combined. A switching means 3 is provided for switching a flow state of a fluid so that the large flow rate is measured by the large flow rate measurement part 1 or the large flow rate measurement part 1 and the small flow rate measurement part 2, and the small flow rate is measured by the small flow rate measurement part 2. When the flow rate is small, the flow rate is correctly measured by the small flow rate measurement part 2. When the flow rate is large, the flow rate is correctly measured by the large flow rate measurement part 1 or, by the large flow rate measurement part 1 and small flow rate measurement part 2. Accordingly, both the large flow rate and the small flow rate can be correctly measured in a wide range.