A non-aqueous electrolyte secondary battery including: a positive
electrode; a negative electrode; a separator interposed between the
positive electrode and the negative electrode; a non-aqueous electrolyte;
and a porous insulating film adhered to a surface of at least one
selected from the group consisting of the positive electrode and the
negative electrode, the porous insulating film including an inorganic
oxide filler and a film binder, wherein the ratio R of actual volume to
apparent volume of the separator is not less than 0.4 and not greater
than 0.7, and wherein the ratio R and a porosity P of the porous
insulating film satisfy the relational formula:
-0.10.ltoreq.R-P.ltoreq.0.30.