a zoom lens lens - barrel is capable of stabilizing movement of a lens holding frame along an optical axis , ensuring retraction of the lens - barrel into the main body , and reducing the size of the zoom lens lens - barrel . a zoom lens lens - barrel which supports at least one of a plurality of lenses in a movable manner along an optical axis direction comprises a pair of first guide shafts provided parallel to an optical axis z direction which support outer periphery of a first lens frame and a second lens frame and a pair of second guide shafts provided parallel to the optical axis z direction and at a different phase position in the lens - barrel plane than the pair of first guide shafts , which support the outer periphery of a third lens frame , a fourth lens frame , and a fifth lens frame .