The present invention provides a separator for a non-aqueous secondary battery including a porous substrate and an adhesive porous layer that is formed at at least one side of the porous substrate and contains the following polyvinylidene fluoride-based resin A and the following polyvinylidene fluoride-based resin B. (1) Polyvinylidene fluoride resin A selected from the group consisting of vinylidene fluoride homopolymers having a weight average molecular weight of from 600,000 to 2,500,000, and vinylidene fluoride copolymers having a weight average molecular weight of from 600,000 to 2,500,000 and containing a structural unit derived from vinylidene fluoride and a structural unit derived from hexafluoropropylene, the total content of structural units derived from hexafluoropropylene in each of the vinylidene fluoride copolymers being 1.5 mol % or less of the total content of structural units in each of the vinylidene fluoride copolymer. (2) Polyvinylidene fluoride resin B containing a structural unit derived from vinylidene fluoride and a structural unit derived from hexafluoropropylene, the total content of structural units derived from hexafluoropropylene in the polyvinylidene fluoride resin B being greater than 1.5 mol % of the total content of structural units in the polyvinylidene fluoride resin B.