PURPOSE: To enable adhesion to be performed wholly without scarcely damaging air permeability and water permeability by the use of a water emulsion adhesive agent for the adhesion of a filter sheet and a mold frame material.

CONSTITUTION: A filter sheet 3 is laid on the surface of mold frame materials 1 and, from the upper part thereof, water emulsion 4 is infiltrated therein which has 30 - 50% of an adhesive component as a solid component; thereafter, moisture is evaporated therefrom by drying and then adhesion is effected via the adhesive component 5 residing in the parts which contact with the surface of the mold frame 1. With respect to the filter sheet 3, threads 3' constituting the construction are mutually secured by the adhesive component 5 remaining in the sheet; simultaneously, spaces 6 obtained between the threads 3' by evaporation of water are formed and, by the formation of the spaces 6, it nearly recovers the intrinsic air permeability and water permeability of the sheet.