To provide a nonaqueous electrolyte secondary battery causing little swelling when left at high-temperature.

This nonaqueous electrolyte secondary battery is composed of a positive electrode active material containing an oxide capable of storing and releasing lithium, a negative electrode and a nonaqueous electrolyte prepared by dissolving a lithium salt in a nonaqueous solvent. In this case, the nonaqueous electrolyte contains 5 vol.% or more of propylene carbonate with respect to the whole solvent, and the positive electrode active material amount per unit area in the positive electrode is set to 15-50 mg/cm2.