To provide flow rate measurement method and device for liquid fluid capable of more accurately measuring consumption amount or supply flow rate of desired liquid fluid with a simple configuration than a conventional flow rate measurement method or the device by improving a defect of a prior art and capable of being easily used in all industrial fields at a lower cost than that of the conventional flow rate measurement method or the device.

A liquid fluid supply system 5 includes a liquid fluid storage section 1, a liquid fluid consumption structure section 2, and a liquid fluid supply path 3. In the liquid fluid supply system 5, a part of the liquid fluid supply path 3 includes liquid fluid supply control means 8 including an injection mechanism member 7 generating a flow of a liquid fluid 6 from the liquid fluid storage section 1 to the liquid fluid consumption structure section 2. In the injection mechanism member 7, a liquid fluid injection coefficient specific to the liquid fluid supply system 5 is set. A flow rate measurement device 100 for liquid fluid measures supply amount of the liquid fluid 6 using the liquid fluid injection coefficient.