Abstract: A lens driving device for controlling the position of a lens setting member according to a distance to an object to be photographed has a lens barrel mounted to undergo movement in the direction of an optical axis, a lens setting member mounted to undergo rotation about the lens barrel and to move the lens barrel in the direction of the optical axis, a biasing spring for applying a biasing force for biasing the lens setting member in one direction, a ratchet engaging with the lens setting member to undergo rotation therewith, a retaining member having a pair of engaging pawls disposed to alternately engage with the ratchet to prevent rotation of the ratchet due to the biasing force of the biasing spring, an electromagnetic actuator for applying a first driving voltage for maintaining the retaining member in an engaged state and a second driving voltage for rocking the retaining member to alternately engage the pawls with the ratchet to cause the biasing spring to rotate the ratchet in a stepwise manner during