Abstract: An apparatus for inhibiting cross talk under a difference mode is disclosed, in which undesired cross talk due to the adjacency and non-uniformness of the untwisted portion are eliminated when untwisting the UTP (unshielded twisted pair) cables to insert the UTP cables into plug holes. In four pairs which are liable to generate cross talk due to their adjacency, artificial patterns are disposed on the front and rear faces of a PCB in such a manner that an effect the same as an insertion of a spiral capacitor should be produced, so that the cross talk in the interfering lines would meet the regulated value. In arranging a plurality of transmission lines to improve the radio wave transmission performance, the four pairs of the lines are disposed on the front and rear faces of the PCB more specifically, spiral capacitors are disposed as follows. A third line is disposed on the rear of a first line, a fifth line is disposed on the rear of a third line, and an eighth line is disposed on the rear of a sixth line.