The movement analysis becomes easy and the control of all the movement systems is realized better through the initialization of the multiple coordinate systems. The fundamental body portion 6 is coupled to a foot portion 5 through a first joint portion 7, a first link 3, a second joint portion 8, a second link 4, and a third joint portion 9. The rigidity of the first link 3 is lower than that of the fundamental body portion 6, and the rigidity of the second link 4 is lower than that of the second link 4. It is possible to position the second link 4 and the foot portion 5 in a high precision to a mechanical origin which is predetermined to the fundamental body portion, for the reason of the rigidity relation. Handle portions 13 are coupled in two positions to the fundamental body portion 6. When the whole posture is initialized based on the mechanical origin, the center of gravity G of the whole robot is located between two vertical planes containing the two positions. In the initialization, a first joint portion 7, a second joint portion 8, and a third joint portion 9 are located between the two vertical planes. Thus, because the whole balance is taken, the origin adjustment is easy.