A dynamic damper for attenuating torsional vibration of a rotary member irrespective of oscillation angle of a pendulum.The dynamic damper 1 comprises a pendulum 3 oscillated by torque pulse of the rotary member 2, and oscillation frequency of the pendulum 3 is tuned to a torque pulse frequency. In a suspending member of the pendulum, a pivot point P and an oscillation length L of the pendulum 3 are changed in accordance with an increase in an oscillation angle of the pendulum 3. Therefore, a mass of the pendulum 3 is allowed to oscillate while tracing an approximate cycloid path so that the torsional vibration of the rotary member 2 can be attenuated irrespective of oscillation angle of the pendulum 3.