Moisture absorbent is embedded in a sheet-type support by a centrifugal force. A gas permeable sheet is fixed to one face of the support via an adhesive layer and a protection sheet is fixed to the other face of the sheet-type support via an adhesive layer. In this way, a moisture absorbent sheet is previously prepared. When in an organic EL display, the protection sheet is removed from the moisture absorbent sheet, the adhesive layer comes into contact with an opposed face of a seal cap and the moisture absorbent sheet is fixed to the opposed face. The seal cap is put on a transparent insulating substrate in which an anode layer, organic EL lamination body, and a cathode layer are laminated. The seal cap comes into contact with the transparent insulating substrate via seal resin of ultraviolet-curable type and ultraviolet rays are irradiated so as to complete the organic EL display.