A conductive adhesive agent of the invention contains an elution preventing film-forming agent 4, which becomes reactive after electric continuity through a conductive particle 3 appeared in the conductive adhesive agent when a binder resin 2 is being hardened, to thereby form an elution preventing film 5 on a surface of the conductive particle 3. By using this conductive adhesive agent, the packaging structure is made migration resistant and sulfurization resistant.