The present invention aims to provide an additive for a non-aqueous electrolyte solution with excellent storage stability capable of forming a stable SEI on the surface of an electrode to improve cell performance such as a cycle performance, a discharge/charge capacity, and internal resistance, when the additive is used for electrical storage devices such as non-aqueous electrolyte solution secondary cells and electric double layer capacitors. The present invention also aims to provide a non-aqueous electrolyte solution containing the additive for a non-aqueous electrolyte solution and to provide an electrical storage device using the non-aqueous electrolyte solution. The present invention is an additive for a non-aqueous electrolyte solution, comprising a compound that has a structure represented by the formula (1-1) or (1-2): in which A represents CmH(2m−n)Zn, m being an integer of 1 to 6, n being an integer of 0 to 12, and Z representing a substituted or unsubstituted alkyl group, a silyl group, a phosphonic acid ester group, an acyl group, a cyano group, or a nitro group, the compound having a lowest unoccupied molecular orbital energy of −3.0 to 0.4 eV, a standard enthalpy of formation of −220 to −40 kcal/mol, and an enthalpy change with hydrolysis reaction of −5 to 5 kcal/mol.