A lens barrel of the present invention is a lens barrel holding a photographing optical system which is a zoom lens constituted by five groups and includes: a cylindrical cam barrel arranged to be rotatable around an optical axis; a first lens driving section driving the cam barrel around the optical axis; a plurality of first cam grooves carved on an outer circumferential surface of the cam barrel; and a plurality of second cam grooves carved on an inner circumferential surface of the cam barrel. A first lens group holding barrel has a plurality of cam followers that are recessed in the first cam grooves; and each of a second lens group holding barrel and a third lens group holding barrel has a plurality of cam followers that are recessed in the second cam grooves.