In a porous layer of the present invention, in a case where the porous layer is divided into 32 sections, a degree of variability in voidage that is measured in the 32 sections is 16.0% or lower. Each of the 32 sections is a rectangular parallelepiped whose longitudinal length is 2.3 μm, transverse length is 2.3 μm, and thickness is identical with that of the porous layer. The porous layer of the present invention and a separator formed by laminating the porous layer are suitable as a member for a non-aqueous electrolyte secondary battery that has an excellent cycle characteristic.