A lens barrel includes a light amount adjuster capable of adjusting a light amount of a lens system and which can be moved in the optical axis direction of the lens system, an adjacent member adjacent to the light amount adjuster and which can be moved relatively in the optical axis direction and a flexible wiring board one end of which is fixed to the light amount adjuster and of which the other end is led out through the adjacent member, wherein a fixed portion of one end of the flexible wiring board is fixed to the light amount adjuster in a two-dimensional fashion and an intermediate portion of the flexible wiring board is bent like a U shape at a space portion formed between the light amount adjuster and the adjacent member, inverted approximately 180 degrees and opposed to the fixed portion.