PURPOSE: To carry out a soft landing by providing a timed pressure applying device for generating a lifting force nearly equal to the weight of a person for a specified time period from a moment at which the person kicks the ground with his feed and jumps up, so as to increase the lifting force from the kick-up moment in order to hold the person under zero gravity, and then to return him to its original condition in the vicinity of the end of a stroke of a balancer.

CONSTITUTION: There are provided a pilot valve 8 having two stages compression springs 18, 21 for feeding an pneumatic regulating signal to a source pressure intake booster relay 4 attached to an air cylinder 1 which holds a lower suspending part 2, and a timed pressure applying device 12 for the valve. A push-type electric solenoid 31 constituting a third pressure applying device, presses a lever 22 by means of a pressure applying spring 35 by way of a lever 33 having its fulcrum 33 and a tension rod 34. An acceleration detecting sensor 41 is composed of an inertia mass 42 which is floated by a spring 43, and is set in such a condition that a microswitch will be contact at once. Accordingly, when an upward acceleration is detected, the switch is turned on so as to energize the solenoid by way of a timer 45. With this arrangement, when a person jumps up from the ground, a larger jumping force can be obtained since he has a large ground contact area by his feet, thereby it is possible to jump up to a high level.