To facilitate positioning of a support metal fitting of a structure to be measured and a mount member of a support structural body and achieve a compact and simple constitution, by setting a leaf spring which bridges a plurality of support members hung from a mount plate.

A support structural body unit 1 used for measurements has a measurement support structural body 2 and a load cell 3. The structural body 2 comprises a rectangular mount plate 4, two supporting members 5, 6 hung at both end parts of shorter sides of the mount plate and a leaf spring 7 of a thin metallic element bridging the support members 5, 6. A pedestal 8 is set at a central part of the mount plate 4, which has a recess 8a at a central part to mount and fix the load cell 3. An error in registration between a measurement hopper or the like structure to be measured and the structural body unit 1 is absorbed by a recess 10a of an upper washer 10, thereby facilitating the registration. A force in a horizontal direction because of a weight of the measurement hopper is absorbed by the support members 5, 6 via the leaf spring 7, and therefore no horizontal force is applied to the load cell 3.