PROBLEM TO BE SOLVED: To provide a volume measuring device capable of more accurately measuring the volume of an object to be measured, an endoscope washing and disinfecting device having the volume measuring device and a volume measuring method.SOLUTION: A volume measuring device 1 includes: a pressure pump 21a for pressurizing a container 3 capable of storing an object 5 to be measured and liquid 34 a pressure sensor 22a for measuring the internal pressure of the object 5 to be measured a water gauge 32 for detecting the water level of the liquid 34 stored in the container 3 a liquid introduction part 4a a liquid discharge part 4b a pressure sensor 22b for measuring the internal pressure of the container 3 and a control part 27. The control part 27 adjusts liquid quantity 34 in the container 3 such that the internal pressure of the object 5 to be measured matches the internal pressure of the container 3 (S2 to S4), and calculates the volume of the object 5 to be measured from the information of the water level of the liquid 34 in the container 3 (S5 to S6).SELECTED DRAWING: Figure 1
