PURPOSE: To provide an energy storing device for power generation which can be connected to a motive power energy source with uneven rotation frequency such as a wind mill mechanism, can pick up an almost even output rotation frequency while converting the motive power energy into a tension applying force, and can obtain a stable power constantly by driving a generator with the even output rotation frequency.

CONSTITUTION: Plural energy accumulating mechanisms 12 to convert a motive power energy into a torque, and then to accumulate it as an energizing force are provided, and the energy accumulating mechanisms 12 are provided with an input rotating member 16, an energy accumulating member 18 to accumulate the torque of the input rotating member as an energizing force, a tension river 20 to accumulate the energizing force to the energy accumulating member linking with the input rotating member, and an output member 22 to output the energizing force in the energy accumulating member. A stable power can be obtained by rotating a generator by outputting an almost even output torque in order constantly, while accumulating the torque of the wind mill as the energizing force.