To provide a pendulum driving device which swings in irregular cycles.

This pendulum driving device is provided with a magnetic member 10 which gives the largest damping force in the center of the amplitude of a pendulum and then the attracting force of a permanent magnet 5 provided nearby the lower end of a pendulum lever 4 in swing motion is made to operate. Electric power is supplied to a driving coil 7 once while the pendulum swings several times and then the motion of the pendulum is attenuated with the magnetic attracting force operating between the permanent magnet 5 and magnetic member 10; and the electric power is supplied to increase the amplitude which is decreasing, thereby giving a variation to the pendulum motion. Since the desired cycle vibration can be obtained by controlling the supplied electric power and selecting the installation position of the magnetic member, wide-range uses can be expected.