A structure for automatically rotating a spiral rod is provided. The structure allows a dusting cloth to be turned into a spiral shape along the spiral rod by rotating a rotating element, and, while the rotating element is being rotated, a torsion spring generates a restoring torque. Once the rotating element is no longer rotated, a pulling element pressing against the teeth inside the rotating element retains the rotating element and thus keeps the dusting cloth in the spiral shape. When the pulling element is subsequently pulled away from the teeth of the rotating element, the rotating element automatically rotates in the reverse direction due to the restoring torque of the torsion spring.