A nonaqueous electrolyte secondary battery is provided, which includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution containing a supporting salt having ionic conductivity, wherein the positive electrode contains an electrically conductive polymer, the negative electrode contains a carbonaceous material capable of lithium ion insertion/desertion, and the electrolyte solution contains a negative electrode film-forming agent. Consequently, the nonaqueous electrolyte secondary battery, which uses the electrically conductive polymer in the positive electrode and the carbonaceous material in the negative electrode, has an excellent weight energy density and can effectively suppress deterioration of battery performance.