To secure initial power by generating electric power in its launching tube in a flying object which gyratingly flies.

A self-gyration type initial generator incorporated in an object which gyratingly flies generates electric power by using the difference in number of gyration between a stator 2 fixed to the object side and a rotor 10 rotatably held by a bearing 11 on the center axis P of the gyration of the object. The difference in number of gyration can be generated by the inertia existing in the rotor 10 when the stator 2 is started the gyration.