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.