To provide a lithium secondary battery superior in mass productivity and having a high discharge capacity, when it is discharged at a high rate by providing a negative electrode containing a two-dimensional porous body having the tensile strength and numerical aperture of specific ranges and made of copper or a copper alloy as a current collector.

The tensile strength of a two-dimensional porous body made of copper or a copper alloy is set to 4 N/mm2 or above, and the numerical aperture is set to 40-80%. Positive electrode layers 5 are carried on both faces of a negative electrode current collector 6 made of this two-dimensional porous body to form the positive electrode 1 of a polymer lithium secondary battery. Negative electrode layers 7 are carried on both faces of the negative electrode current collector 6, made of the two-dimensional porous body to form a negative electrode 2. The positive electrode current collector 4 of the positive electrode 1 is extended into a band shape to form a band-like positive electrode terminal 8, and the negative electrode current collector 6 of the negative electrode 2 is extended into a band shape to form a band-like negative electrode terminal 9. A layered product constituted of the positive electrode 1, negative electrode 2 and an electrolyte layer 3 is sealed in an outer packaging film 11.