A collapsible lens barrel includes a first holding frame (2) for holding a first lens group (L1), a second holding frame (5) for holding a second lens group (L2) that is disposed on an image plane side with respect to the first lens group (L1), an actuator (6) for moving the second holding frame 5 in an optical axis direction, and a tubular cam frame (17) including a plurality of cam grooves that are formed at substantially equal intervals around a circumferential direction for moving the first holding frame (2) in the optical axis direction. The actuator (6) is attached to a portion in the cam frame (17) where the cam grooves are not formed. The first lens group (L1) is moved using the cam grooves, and the second lens group (L2) is moved using the actuator (6), so that a faster zooming speed and a lower zooming noise can be achieved.