Discloses are a transmission line having variable characteristic impedance and a combiner configured to combine a plurality of filter by use of the transmission line. The transmission line in accordance with an embodiment of the present invention includes: a first filter junction being connected with a first RF filter and configured to obtain an output signal of the first RF filter; a second filter junction being connected with a second RF filter and configured to obtain an output signal of the second RF filter; a first variable impedance section in which a phase of the output signal of the first RF filter is matched with a preset phase; and a second variable impedance section in which a phase of the output signal of the second RF filter is matched with the preset phase.