To provide a non-aqueous electrolyte solution for a non-aqueous secondary battery which has an improved flame retardancy without deteriorating the performance of the non-aqueous secondary battery.

The non-aqueous electrolyte solution is represented by the general formula (I). (R1 and R2, which may be the same or different, and are selected from a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkoxy group, a lower alkoxycarbonyl group, a lower alkylcarbonyl group, a lower cycloalkyl group, or an aryl group while they may have a substituent; n is 0 or 1 and when n is 0, R3 is selected from a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkenyl group, a lower alkoxy group, a lower alkoxycarbonyl group, a lower alkylcarbonyl group, a lower cycloalkyl group, or an aryl group while they may have a substituent; and when n is 1, R3 and R4 are defined as the same as R1 and R2.)