PURPOSE: To permit a walking person to return to a prescribed position even if he deflects from the upper and lower limit positions by reducing a suspension force when the walking person deflects from the upper limit position, while increasing the suspension force when the walking person deflects from the lower limit position.

CONSTITUTION: A pantagraph mechanism having a parallelogram which deforms according to the suspension position of a walking person is constituted of four arm members 1-3 and 10. A walking person suspending means 16 is suspended at the cross point of the first arm 3 of the pantagraph mechanism. Further, the cross point of the second arm 1 is pivotally supported by a fixed supporting point 7. Further, a suspension force for suspending the walking person is generated by an air cylinder 6 connected at the cross point of the third arm 2. The suspension force is controlled to a prescribed value by a control means consisting of limit switches 23 and 24, and when the walking person deflects from an upper limit position, the suspension force is reduced' than a prescribed value, while if the walking person deflects from a lower limit position, the suspension force is increase up to a prescribed value. Accordingly even if the walking person deflects from the upper and lower limit positions, the walking person can be return to a prescribed position.