DIELECTRIC FILTER

PROBLEM TO BE SOLVED: To provide the dielectric filter at low cost in which a harmonic attenuation characteristics is improved, without deteriorating a filter characteristics and the number of components is not increased. SOLUTION: A plurality of resonator use a through-hole 12 and a through- hole 13 for input output terminals placed at both ends of the throughhole 12 are provided to a dielectric block 11 in the lengthwise direction, a conductor layer F is formed to the inner face of each through-hole and the outer face of the block. One end face conductor of the resonator use the through-hole 12 is removed to form λ/4 resonators 12a, 12b, upper lower end face conductor of the through-hole 13 are removed to form input-output electrodes 13a, 13b. In the integrated multi-stage structured dielectric filter as above, a length D of at least one of the inner conductors for the through-hole 13 for input output terminals is selected to be a required length D, in resonance with a wavelength of λ/2.