A lead wire for a nonaqueous electrolyte battery has a conductor, and an insulating film having a plurality of layers and covering at least a part of the outer peripheral surface of the conductor, wherein the insulating film has a conductor-covering layer laminated on a surface of the conductor, a first insulating layer laminated on an outermost surface of the insulating film, and a second insulating layer laminated on an inner surface of the first insulating layer; the conductor-covering layer contains an acid-modified polyolefin; and the ratio (E1/E2) of an elastic modulus E1 of the first insulating layer at any one temperature in the range of 80° C. or more and 125° C. or less to an elastic modulus E2 of the second insulating layer at the same temperature as in the first insulating layer, is 0.10 or more and 10.00 or less.