To provide a lens barrel, capable of easily achieving further shrinkage states without changing the basic constitution of making two lead screw shafts rotate and making a first lens group and a second lens group move by using one driving source.

A first holding frame 304 which holds a first lens group by a first screw shaft 301 and second screw shaft 313 rotated by the driving source and a second holding frame which holds a second lens group are interlocked and are made movable in the optical axis direction. When the second holding frame approaches the first holding frame 304, the first holding frame presses a rack member 309 and releases the interlocking of rack teeth 309a and the first screw shaft 301, thereby permitting free movement of the first holding frame.