A lithium secondary battery comprising: an electrode assembly comprising a cathode, an anode, and a porous substrate interposed therebetween as a separator and made of polyethylene, polypropylene, polybutylene, polypentene, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalate or a mixture of any thereof; a battery case for receiving the electrode assembly; and a non-aqueous electrolyte solution being introduced in the battery case to be impregnated into the electrode assembly, wherein the anode is a lithium electrode comprising: an electrode composite comprising a porous metallic current collector, and lithium metal inserted into pores present in the metallic current collector, wherein the lithium metal is inserted in an amount of 1 to 50 wt% based on the total weight of the electrode composite; and a protective membrane for lithium ion conduction, the protective membrane being formed on at least one surface of the electrode composite and being made of polyethylene oxide, polyacrylonitrile, polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene (PVDF-co-HFP), LiPON, Li 3 N, Li x La 1-x TiO 3 (0 < x < 1), Li 2 S-GeS-Ga 2 S 3 or a mixture of any thereof. an electrode assembly comprising a cathode, an anode, and a porous substrate interposed therebetween as a separator and made of polyethylene, polypropylene, polybutylene, polypentene, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalate or a mixture of any thereof; a battery case for receiving the electrode assembly; and a non-aqueous electrolyte solution being introduced in the battery case to be impregnated into the electrode assembly, wherein the anode is a lithium electrode comprising: an electrode composite comprising a porous metallic current collector, and lithium metal inserted into pores present in the metallic current collector, wherein the lithium metal is inserted in an amount of 1 to 50 wt% based on the total weight of the electrode composite; and a protective membrane for lithium ion conduction, the protective membrane being formed on at least one surface of the electrode composite and being made of polyethylene oxide, polyacrylonitrile, polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene (PVDF-co-HFP), LiPON, Li 3 N, Li x La 1-x TiO 3 (0 < x < 1), Li 2 S-GeS-Ga 2 S 3 or a mixture of any thereof. an electrode composite comprising a porous metallic current collector, and lithium metal inserted into pores present in the metallic current collector, wherein the lithium metal is inserted in an amount of 1 to 50 wt% based on the total weight of the electrode composite; and a protective membrane for lithium ion conduction, the protective membrane being formed on at least one surface of the electrode composite and being made of polyethylene oxide, polyacrylonitrile, polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene (PVDF-co-HFP), LiPON, Li 3 N, Li x La 1-x TiO 3 (0 < x < 1), Li 2 S-GeS-Ga 2 S 3 or a mixture of any thereof.