To provide an antenna trap that can simply be configured and miniaturized.

An upper antenna element 11 whose lower part is formed with an extended diameter part 11b is inserted from below into a lower part of a 1st insulation cylinder section 12b of a cylindrical shape. Then a 2nd insulation cylinder section 12c with a lower antenna element 13 inserted thereto is inserted from below into the extended diameter path 11b inserted to the 1st insulation cylinder section 12b. Furthermore, an end of a trap coil 12a wound on an outer circumferential face of the 1st insulation cylinder section 12b is wound around base ends of the upper antenna element 11 and the lower antenna element 13 and connected to assemble a trap section 12. The upper part of the lower antenna element 13 and the extended diameter part 11b formed to the lower part of the upper antenna element 11 form a small-sized coaxial capacitor.