Provided is a separator for a secondary battery including: a porous substrate; and a coating layer formed on the porous substrate, wherein the coating layer includes a plurality of inorganic particles and a binder for binding the plurality of inorganic particles, and the binder includes a copolymer of a monomer mixture including an acrylamide-based monomer, a vinyl cyanide monomer, and an acrylic monomer having a carboxyl group.