A coupler for a coaxial cable, comprising: a section of a coaxial line made of a central conductor and an external conductor with a dielectric insulator arranged therebetween; wherein the coaxial cable is made with an insulating layer between its inner conductor and its outer conductor and with a dielectric jacket on the outer conductor, wherein the central conductor of the section of the coaxial line being intended for electric capacitive coupling with the inner conductor of the coaxial cable, and the external conductor being intended for electric capacitive coupling with the outer conductor of the coaxial cable; wherein the central conductor of the section of the coaxial line with the dielectric insulator is electrically capacitive coupled to the inner conductor of the coaxial cable via an opening made in the dielectric jacket, the outer conductor, the insulating layer and the inner conductor of the coaxial cable wherein the central conductor with the dielectric insulator of the section of the coaxial line are arranged in the opening made in the inner conductor of the coaxial cable, the coupler further comprises a metal plate, which inner surface facing the dielectric jacket of the coaxial cable is made as to its shape and dimensions so as to correspond to the shape and dimensions of the dielectric jacket of the coaxial cable, the metal plate being provided at least with one connection element ensuring its mounting directly to the dielectric jacket of the coaxial cable, the opening in the dielectric jacket, the outer conductor, the insulating layer and the inner conductor of the coaxial cable being made with the diameter equal to the outer diameter of the dielectric insulator, the metal plate and the external conductor of the section of the coaxial line being connected therebetween and having no galvanic contact with the outer conductor of the coaxial cable. a section of a coaxial line made of a central conductor and an external conductor with a dielectric insulator arranged therebetween; wherein the coaxial cable is made with an insulating layer between its inner conductor and its outer conductor and with a dielectric jacket on the outer conductor, wherein the central conductor of the section of the coaxial line being intended for electric capacitive coupling with the inner conductor of the coaxial cable, and the external conductor being intended for electric capacitive coupling with the outer conductor of the coaxial cable; wherein the central conductor of the section of the coaxial line with the dielectric insulator is electrically capacitive coupled to the inner conductor of the coaxial cable via an opening made in the dielectric jacket, the outer conductor, the insulating layer and the inner conductor of the coaxial cable wherein the central conductor with the dielectric insulator of the section of the coaxial line are arranged in the opening made in the inner conductor of the coaxial cable, the coupler further comprises a metal plate, which inner surface facing the dielectric jacket of the coaxial cable is made as to its shape and dimensions so as to correspond to the shape and dimensions of the dielectric jacket of the coaxial cable, the metal plate being provided at least with one connection element ensuring its mounting directly to the dielectric jacket of the coaxial cable, the opening in the dielectric jacket, the outer conductor, the insulating layer and the inner conductor of the coaxial cable being made with the diameter equal to the outer diameter of the dielectric insulator, the metal plate and the external conductor of the section of the coaxial line being connected therebetween and having no galvanic contact with the outer conductor of the coaxial cable.