A positive electrode active material of a nonaqueous electrolyte secondary battery is composed of lithium-cobalt composite oxide containing at least one of zirconium, titanium, aluminum, and erbium, and the nonaqueous electrolyte includes an additive expressed by General Formula (1) having an acetylene group and a methylsulfonyl group at each end of the molecule. It has the effect of forming an SEI surface film as with the case of VC or the like, as well as having a higher oxidation resistance than that of VC or the like. Thus the nonaqueous electrolyte secondary battery employing as positive electrode active material a lithium-cobalt composite oxide with a particular dissimilar metallic element added, in which decomposition of the nonaqueous electrolytic solution during storage at high temperature in a charged state is suppressed, and there is little battery swelling is provided.