DIELECTRIC FILTER

PROBLEM TO BE SOLVED: To obtain the dielectric filter whose pass characteristic in the vicinity of a resonance frequency for harmonics is improved. SOLUTION: The dielectric filter is provided with a base board 4 having input/output terminals 6a, 6b, input/output coupling strip lines 7a, 7b, and a ground pattern 8 as its conductor pattern and with a plurality of 1/4 wavelength coaxial dielectric resonators arranged adjacent to each other on an upper side of the base board 4. In this case, the line width of the input/output coupling strip lines 7a, 7b is formed wider in the vicinity of a part in contact with an open end face of a dielectric material and in the vicinity of a part apart from the open end face by about 2/3 of the length of the resonators than the other parts.