a filter for flitrating molten resin of the invention includes : a cylindrical filtering member formed with a large number of projections and recesses ; and radially arranged rods in a supporter for supporting the cylindrical filtering member at arc - shaped projected portions , and is constructed such that molten resin material is allowed to pass through the filtering member at arc - shaped recessed portions . in this arrangement , it is possible to enhance the resistance of thermoplastic molten resin filter against filtering pressure as well as to ensure a large filtering area . further , the filter may be constructed such that the cross - section of the aforementioned cylindrical member is made greater from the upstream side toward the downstream side . by this configuration , the flow rate of molten resin passing through the unit area of the filtering member is made uniform and consequently the collecting capacity of foreign substances is increased .