To reduce a usage amount of LiPF6 in a nonaqueous electrolyte to the utmost without decreasing characteristics in the case where a positive electrode containing manganese oxide or lithium manganese compound oxide and a negative electrode containing at least lithium are used.

A nonaqueous electrolyte secondary battery is constituted with a positive electrode containing manganese oxide or a lithium manganese compound oxide, a negative electrode containing at least lithium, and a nonaqueous electrolyte containing LiBF4 and LiPF6 in such concentration that the relation of 0.01≤b/(a+b) ≤0.3 is satisfied when the concentration of LiBF4 is represented by (a) (mol/cm3) and that of LiPF6 is represented by (b)(mol/cm3). Average voltage in discharge is preferable to be 3 (V) or higher, and the manganese oxide or the lithium manganese compound oxide contained in the positive electrode is preferable to have spinel type crystal structure.