In a method of forming a synthetic resin structure integral with two-dimensional steel fabric, a warp and woof are made from a steel metal, and these wires are woven in a planar configuration to provide a two-dimensional steel fabric which is then pressed into a flat structure. Two flat structures are set at a metallic mold die, into which a synthetic resin is injected so as to form a synthetic resin body integral with the flat structures. This makes it possible to secure a sufficient space between the flat structures, and spread the synthetic resin fully into the flat structures so as to reinforce a surface of the synthetic resin body with durability and high rigidity. Through the toughness, strength and price of the steel metal, it is possible to provide a marketability with products manufactured by using the present method.