A separator for an electrochemical device including a porous polymer substrate; and a porous coating layer formed on at least one surface of the porous polymer substrate, wherein the porous coating layer comprises inorganic particles and a binder polymer positioned on at least a part of a surface of individual inorganic particles to connect and fix the inorganic particles with one another. The binder polymer comprises a first block having repeating units and a second block having repeating units. A method for manufacturing the same is also provided. The separator shows low resistance, improved adhesion to an electrode and improved swelling property with a solvent.