To perform continuous output of high power energy after starting operation.

A power generating device comprises a plurality of intermittent spiral magnets 21 arranged at equal intervals in the vicinity of the outer periphery of a rotary disc 20 and rotationally energizing the rotary disc 20 through movement of right and left pendulum magnets 8, 9, and 10; and an annular magnet 22 arranged on the inside diameter side of the intermittent spiral magnet 21 in such a manner that height is changed in a peripheral direction and energizing mainly the central pendulum magnets 8, 9, and 10 in a direction in which the pendulum magnets are separated away from a center. A plurality of radial magnets 23 are inclined radially in the annular magnet 22 centering around the center of the rotary disc and raised at different gradients toward the annular magnet 22 side and the rotary disc 20 is rotationally energized through oscillation of the pendulum magnets 8 and 10.