To provide a device capable of accumulating a strong force by a small motor and generating a strong resilient force.

The resilient force generating device 1 is constituted by winding a twist spring 5 around a shaft for pivoting an actuating member 3 with a supporting point and fixed to a housing and by forming a cam follower contacting with a cam outer circumference surface at a cam follower rod end by rolling friction. One end of the twist spring 5 is fixed to a housing and the other end is fixed at an actuator rod 13-1 of an actuating member and the twist spring 5 functions to generate a resilient force by accumulating a force by the rotation of the actuating member and releasing the constraint of the cam follower. In this case, an outer circumference surface profile wherein a normal of the cam circumference surface at a point of the application of a force and a line connecting a supporting point of the actuating member and the rotation axial center of the cam follower is vertical or approximately vertical is provided and a cam and a rotation driving device of the cam for releasing the constraint of the actuating member by its step are provided in the resilient force generating device.