PROBLEM TO BE SOLVED: To provide a flexible container holding device which permits damage to a flexible container to be prevented.SOLUTION: The flexible container holding device 10 includes a pair of storage plates 12a and 12b made of stiff members having one ends engaged openably through rotating shafts. Introduction opening side grooves 14a and 14b engageable with a fluid introduction opening provided in the flexible container, extraction opening side grooves 16a and 16b engageable with a fluid extraction opening provided in the flexible container, a fixing portion permitting the flexible container to be fixed, and a pressure sensor to measure the internal pressure of the flexible container are provided on the inside 20 of each of the storage plates 12a and 12b.
