The authors have developed an exoskeletal motion measurement device for the motion instructing human interface, which underacts master's motions in sports, dances, and the like, leading learners to follow the master's motions. They have also proposed its simple calibration method and developed the monitoring system, which shows the learners the error of the present motions to the target one: it display the synthesized 3-D images in the virtual space by using HMD stereoscopic vision. The effectiveness of the proposed system was confirmed for the motion instruction through the comparative experiments between the cases with and without the instruction support.