A lens drive device having a simple structure and small sized. The lens drive device (1) has a lens holder (3, 5), a drive shaft (21) into which one end of the lens holder (3, 5) is fitted and placed along the direction of the optical axis of lenses (14, 16), and a piezo element (17) provided at a base end (21a) of the drive shaft (21). The base end (21a) of the drive shaft (21) is fixed to a vibrator (19) of the piezo element (17), and the drive shaft (21) is vibrated in the direction of its axis by vibration of the vibrator (19) produced by conducting a pulse current to the piezo element (17). The lens holder (3, 5) is moved in the optical axis direction by using repetition of inertia force and friction force of the holder relative to the drive shaft (21).