PURPOSE: To provide a seaweed-filled sheet capable of being readily used and having a remarkable effect for improving health by filling dried seaweed fine flakes between two front and back skin materials to form a flat sheet-like article.

CONSTITUTION: A seaweed [preferably Rhodophyceae, especially FUNORI (a glue plant)] is dried with sunlight or a drier and cut into fine flakes having appropriate sizes. The fine flakes 1 are filled between two front and back skin materials 2 and 2 such as woven fabrics or non-woven fabrics and the front and back skin materials are integrated by a heat sealing method or with an adhesive to form a flat sheet-like article. When the flat sheet-like article is divided with the heat-sealed portions or adhered portions into small divided lattice and seaweed fine flakes are filled into the respective divided portions to form small bag portions, the flat sheet-like article is used as a sheet having an appropriate size while changing the number of the small bags depending on applications. The shaking of the small bags while used permits the ready mixing activation of the seaweed fine flakes.