A lens barrel including an image capturing optical system, to be extended for image capturing and to be retracted for carrying, including: a first lens unit for capturing an image of a subject; a light-amount control member to control an amount of light which comes from the subject and passes through the image capturing optical system; and second lens unit including at least two lens units which sandwich the light-amount control member on the optical axis; wherein when the lens barrel is extended for image capturing, the first lens unit and the second lens unit exist on the optical axis, while the light amount control member is sandwiched between the two lens units of the second lens unit on the optical axis, and when the lens barrel is retracted, the second lens unit is shifted to the position out of the optical axis.