A flat-panel display device having a transparent first plate and a second plate which are disposed in parallel with each other and cooperate to define therebetween an air-tight space in which light is generated for emission through the first plate, the display device including a sealing material for air-tightly sealing the air-tight space along a periphery of the first and second plates, and metallic thin sheets bonded with the sealing material to end faces of the first and second plates such that the metallic thin sheets cover the end faces. The display device is manufactured by applying the sealing material to the end faces such that a peripheral portion of the air-tight space is filled with a mass of the sealing material, forcing the metallic thin sheets onto the end faces such that the metallic thin sheets cover the end faces, and heating the sheets and the sealing material firing the sealing material for air-tightly bonding together the two plates while bonding the metallic thin sheets to the end faces through the sealing material.