A lens driving mechanism for an image pickup apparatus capable of being reduced in size, and having excellent driving accuracy and tranquility is provided. The lens driving mechanism is characterized in that vibration of a piezoelectric vibration motor is used as a driving source, and the vibration is transmitted to a motor power transmission ring directly or via a gear structure, to rotationally drive a lens driving ring. In a first lens driving mechanism, the motor power transmission ring is rotated by rotating the first transmission gear by use of the vibration of the piezoelectric vibration motor. In a second lens driving mechanism, a thrust bearing is provided on a gear side for rotating the motor power transmission ring, and the gear is rotated by vertically pressing a vibrator of the piezoelectric vibration motor in an urged state against a plane of the gear. In a third lens driving mechanism, the lens driving ring is rotationally driven by directly pressing a vibrator of each of one or more piezoelectric vibration motors in an urged state against the outer periphery of the lens driving ring.