A lens barrel comprises a first frame including an inward flange having an
opening as a light path for a photographic optical system, a
barrier-driving member disposed in the vicinity of the opening, a second
frame disposed inside the first frame and movable along an optical axis
relative to the first frame, a barrier blade movable along with the
rotation of the barrier-driving member between a closed position in which
the barrier blade blocks at least a part of the light path and an open
position in which the barrier blade is retracted from the light path, an
opening-urging member capable of urging the barrier blade towards the
open position and urging the barrier-driving member towards a first
direction, and a closing-urging member capable of urging the barrier
blade toward the closed position. In the event that an external force,
such as photographer's finger, urges the barrier blade toward an open
position, the closing-urging member urges the barrier blade to the closed
portion when the external force is removed.