An incombustible lithium secondary battery, which has excellent battery capacity and high safety, contains a separator provided between a positive electrode and a negative electrode, and a nonaqueous electrolytic solution containing a lithium salt, in which the nonaqueous electrolytic solution employs an ionic liquid as a solvent, and the separator contains an electrically insulating porous inorganic membrane and a substrate. The ionic liquid may contain a bis(fluorosulfonyl)imide anion as an anionic component, and may contain a cation containing a nitrogen atom as a cationic component.