The present invention relates to a lithium secondary battery, comprising a positive electrode; a negative electrode; and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution contains a phosphate polymer represented by the following formula (1): wherein R1 to R5 each independently represents aliphatic hydrocarbon group or fluorinated aliphatic hydrocarbon group, wherein the group may have a substituent, and n represents an integer of 1 or more, with the proviso that when n is 2 or more, two or more R1(s) may be the same as, or different from each other and two or more R4(s) may be the same as, or different from each other; and a fluorinated phosphate represented by the following formula (2): wherein R6 to R8 each independently represents aliphatic hydrocarbon group or fluorinated aliphatic hydrocarbon group, wherein the group may have a substituent, with the proviso that at least one of R6 to R8 is fluorinated aliphatic hydrocarbon group.