NOVELTY - A non-aqueous electrolyte solution for a secondary battery comprises a solvent; and an electrolyte containing a lithium salt, where the solvent contains 4-fluoroethylene carbonate and a chain carboxylic ester of specific formula, where the amount of the chain carboxylic ester is greater than or equal to 20 volume% with respect to the total amount of the solvent, and the amount of the 4-fluoroethylene carbonate is greater than or equal to 7 volume% with respect to the total amount of the solvent.    USE - As non-aqueous electrolyte solution for a secondary battery (claimed), used in mobile information terminals such as mobile telephones, notebook computers and PDAs; and in driving power sources for mobile information terminals as well as to drive power sources for e.g. power tools, in-vehicle power sources for electric automobiles or hybrid automobiles.    ADVANTAGE - The battery exhibits improved performance. The non-aqueous electrolyte solution for secondary battery ensures good electrolyte solution permeability and improves load characteristics and durability of large-coating-amount and high-filling-density battery. The non-aqueous secondary battery electrolyte achieves good load characteristics and high durability in a battery for high-capacity applications and high-power applications. The battery that uses the non-aqueous electrolyte solution of 4-fluoroethylene carbonate and a chain carboxylic ester achieves improvements in load characteristics and durability. By using a mixture of a chain carboxylic ester and 4-fluoroethylene carbonate and restricting the loading amount of the 4-fluoroethylene carbonate, the decomposition reaction of the chain carboxylic ester is inhibited, and thereby the reduction in the viscosity of the electrolyte solution achieved by a chain carboxylic ester is maximized. This makes it possible to ensure good permeability of the electrolyte solution even with a battery for high-capacity applications and high-power applications, and to obtain a non-aqueous electrolyte secondary battery that achieves high capacity, high power, and high durability at the same time.    DETAILED DESCRIPTION - A non-aqueous electrolyte solution for a secondary battery comprises a solvent; and an electrolyte containing a lithium salt, where the solvent contains 4-fluoroethylene carbonate and a chain carboxylic ester of formula R1COOR2, where the amount of the chain carboxylic ester is greater than or equal to 20 volume% with respect to the total amount of the solvent, and the amount of the 4-fluoroethylene carbonate is greater than or equal to 7 volume% with respect to the total amount of the solvent.    R1 and R2= less than or equal to 3C alkyl.    An INDEPENDENT CLAIM is included for a non-aqueous electrolyte secondary battery comprising: a positive electrode; a negative electrode; a separator; and the non-aqueous secondary battery electrolyte solution.