A light shielding piece is supported by a second lens holding frame such that the light shielding piece can rotate and move on a plane which is perpendicular to an optical axis. In a shooting state, a through hole formed in the second lens holding frame is closed to establish a light shielding state. In a retracted state, on the other hand, a first auxiliary shaft passing through a through hole of the second lens holding frame pushes the light shielding piece to generate a component force. The generated component force rotates and moves the light shielding piece on a plane which is perpendicular to the optical axis, and the lens barrel is brought into an opened state where the through hole is not blocked.