PURPOSE: To mold a molded product of uniform strength and electromagnetic wave masking effect by means of uniform dispersion by retaining powder or grains of thermoplastic resin in the spaces of a structures constituted of conductive fibers entangled at random such as metallic fibers, metal plated non-metallic fibers or the like.

CONSTITUTION: An air-permeable network-shaped structure A is constituted of point contact or line contact of conductive fibers 1 entangled at random, and solid contents 2 are retained in its spaces. Such a sheet is heated, melted and used as a molding material for embossing. The conductive fibers 1 are discountinuous single fibers of 1W18μm diameters, and anticorrosion metallic fibers or anticorrosion plated iron fibers, or non-metallic fibers metal plated with copper, nickel or the like are used. As for the thermoplastic resin included in a solid content 2, synthetic resin powder or grains are used. Conductive fibers M of 5W50mm length and powder or grains P of thermoplastic resin of 0.3W2.0mm grain diameters are floated in the liquid mediums and dispersed therein, and floating substances F are removed and then its liquid content is removed to form a web W to manufacture a sheet.