A lens position adjusting device of a lens barrel includes a stationary ring, and a manual rotating ring which is screw-engaged with the stationary ring to be manually rotatable about an optical axis to move a movable lens group in the optical axis direction, wherein the manual rotating ring includes an operating ring member; and a sub-ring member which is screwed into the stationary ring, wherein the operating ring member and the sub-ring member are coupled to each other so that a relative rotation position therebetween about the optical axis is adjustable.