A lens barrel having an increased strength against external impact. The lens barrel is configured to move in an optical axis direction. A photographic lens unit moves in the optical axis direction. A cylindrical unit is engaged with the photographic lens unit, and has an outer periphery formed thereon with a first cam groove followed by the photographic lens unit. The cylindrical unit performs rotation to thereby move the photographic lens unit in the optical axis direction. A rectilinear motion-causing restriction member is engaged with the cylindrical unit to restrict motion of the photographic lens unit to rectilinear motion. A second cylindrical unit is disposed around the photographic lens unit and the cylindrical unit to guide the photographic lens unit for rectilinear motion. A second rectilinear motion-causing restriction member restricts motion of the rectilinear motion-causing restriction member and the second cylindrical unit in a direction of rotation.