An object of the invention is to provide a separator for a nonaqueous secondary battery, which has good adhesion to electrodes, is capable of ensuring sufficient ion permeability even after attachment to electrodes, and further includes an adhesive porous layer having dynamic physical properties sufficient to withstand heat pressing and a uniform porous structure. The separator for a nonaqueous secondary battery of the invention includes a porous substrate and an adhesive porous layer that is formed on at least one side of the porous substrate and contains a polyvinylidene-fluoride-based resin. The separator for a nonaqueous secondary battery is characterized in that the adhesive porous layer has a porosity of 30 to 60% and an average pore size of 1 to 100 nm.