The present disclosure relates to a separator for an electrochemical device and an electrode assembly comprising the same. More particularly, the present disclosure relates to a separator with improved interfacial adhesion with electrode and an electrode assembly comprising the same. The adhesion layer according to the present disclosure includes a first layer contacting a surface of the separator and a second layer formed on a surface of the first layer and contacting with an electrode, the first layer includes a polymer resin with a fluorine-containing monomer, and the second layer includes a polymer resin having a lower dissolution rate in an electrolyte solution for an electrochemical device than the polymer resin included in the first layer.