Provided is a non-aqueous-secondary-battery separator including: a microporous membrane; and an adhesive porous layer which is provided on one or both surfaces of the microporous membrane and includes a fibrillar polyvinylidene fluoride resin, in which an average hole diameter acquired from the specific surface area of the microporous membrane is greater than 90 nm and equal to or smaller than 250 nm, peeling strength between the microporous membrane and the adhesive porous layer is equal to or greater than 0.10 N/cm, and a fibrillar diameter acquired from the specific surface area of the adhesive porous layer is from 50 nm to 70 nm.