Separator with organic/inorganic porous coating layer for electrochemical device, and electrochemical device including same

A separator for an electrochemical device, in which the separator includes a separator substrate and an organic-inorganic composite porous coating layer on at least one surface of the separator substrate. The separator substrate is a porous film including a polyolefin-containing polymer. The organic-inorganic composite porous coating layer includes a polymer resin particles and inorganic particles, in which each particle of the polymer resin particles includes a polyvinylidene fluoride (PVDF)-containing polymer and an acrylic polymer, and the PVDF-containing polymer has a Hansen solubility parameter (HSP) value of 13 or less and 1 or more.