The authors propose a method for measuring a micro force using a micro manipulator with low rigidity. In order to understand micro scale phenomena and design better micro devices, we have to do much more strength tests or destructive tests on micro objects, such as to apply some force and detect its behavior, response or deflection. We developed a system to move a probe along 3 axes. The tip end of the manipulator could be shaped into a suitable shape for a target. Using the system, we carried out three strength tests of micro objects, such as measuring mechanical properties of nanowire, shear strength of fixed abrasive grains and mechanical strength of chromosomes. Through these demonstrations, we confirmed the validity of our proposal.