A retractable lens (1) and a swingable lens retracting device (2) thereof are provided. The retractable lens has first, second and third lens groups (L1, L2, L3) constituting a photographing optical system. The swingable lens retracting device consists of a second lens group moving frame (21) and a second lens group holding frame (22) rotatably received in the second lens group moving frame via a pivot shaft (221). A pair of torsion springs (224) is mounted on respective opposite ends of the pivot shaft. When the retractable lens is retracted back to a retracted state, the second lens group is biased by the swingable lens retracting device to an off-axis space radially outside a common optical axis of the photographing optical system with its optical axis being orthogonal to the common optical axis. The transition between a retracted position and a photographing position of the second lens group is accomplished by the resilient restoring force of the torsion springs.