Disclosed is an organic/inorganic composite porous film comprising: (a) inorganic particles; and (b) a binder polymer coating layer formed partially or totally on surfaces of the inorganic particles, wherein the inorganic particles are interconnected among themselves and are fixed by the binder polymer, and interstitial volumes among the inorganic particles form a micropore structure. A method for manufacturing the same film and an electrochemical device including the same film are also disclosed. An electrochemical device comprising the organic/inorganic composite porous film shows improved safety and quality.