Nonaqueous electrolyte solution battery lead wire and nonaqueous electrolyte solution battery

A nonaqueous electrolyte solution battery lead wire comprising:

• a conductor;
• and
• an insulating film having one or a plurality of layers and covering at least part of an outer peripheral surface of the conductor,
• wherein the conductor has a conductor film covering at least part of a surface thereof,
• the conductor film contains a trivalent chromium compound including chromium hydroxide and a metal element,
• a ratio of a mass of chromium contained in the chromium hydroxide per unit area [mg/m2] to a mass of chromium contained in the trivalent chromium compound per unit area [mg/m2] is 0.30 to 0.90 at an outermost surface of the conductor film,
• the insulating film has an innermost layer stacked on a surface of the conductor film,
• the innermost layer contains, as a main component, a resin component including maleic anhydride-modified polypropylene, and
• an acid modification ratio of the resin component is 0.02% by mass to 0.50% by mass.