Disclosed is an organic electroluminescent (EL) device for enhancing the luminous efficiency. A first electrode is formed on a substrate. A CVD insulating film of low dielectric constant having an opening exposing the first electrode is formed on the first electrode and the substrate. An organic EL layer and a second electrode are sequentially stacked on the opening. A wall surrounding a region of the organic EL layer is formed of the CVD insulating film of low dielectric constant, the surface treatment of the pixel electrode can be performed using O2 plasma enhance luminance properties.