LENS BARREL, AND OPTICAL INSTRUMENT HAVING THE LENS BARREL

PROBLEM TO BE SOLVED: To reduce the barrel diameter of a whole lens barrel even when a motor for driving a movable lens for zooming etc., of a photographing optical system is provided. SOLUTION: A rear fitting sleeve part 15a and a forward fitting sleeve 15b are fitted to a guide bar 16b to move a second group barrel to hold a zooming lens group straight, are fitted to a guide bar 16b, and when the second group barrel 15 is moved, the rear fitting sleeve part 15a is not extended backward of a blur correction unit 14 as a shift part, the forward fitting sleeve 15b is overlapped at the thrust position on the first group lens to form a forward lens to be held by a fixed barrel 11, a zoom motor 19 directs a motor body part 19a forward, and is fitted to the fixed barrel 11 so as to be overlapped at the thrust position with the forward lens, and a part backward of the zoom motor 19 is tapered with the lens barrel diameter reduced.