A color conversion type multi-color organic EL display panel is provided in which the lifetime of an organic EL light emitter is improved by preventing migration of moisture to the organic EL light emitter and dispersing heat generated during driving well. The display utilizes a color-converting/filter substrate that includes a transparent supporting substrate, color-converting/filter layers of a single type or a plurality of types arranged on the supporting substrate, a polymeric film layer that covers the color-converting/filter layers and is formed transparent and flat, and a transparent inorganic film layer that is formed on the polymeric film layer. The inorganic film layer is a laminate of one or a plurality of metallic film(s) or metal oxide film(s), and one or a plurality of insulating film(s) each containing at least one of Si and Al and at least one of O and N.