Abstract: The bandpass filter according to the present invention includes a housing having a plurality of cavities, wherein said plurality of cavities are isolated from each other by partitions and wherein each said partition have a coupling window; input/output connectors formed at both ends of said housing so as to pass output signals from a transmitter; coupling loops connected to said input/output connectors so as to excite an applied signal power and to combine resonance modes; dielectric resonators installed in said cavities of said housing so as to resonate a signal power transmitted from said coupling loop to the desired frequency band, said dielectric resonators including: a first resonator group formed in both said cavities which are adjacent to said coupling loops; and a second resonator group formed in said cavities which are positioned between both said cavities which are adjacent to said coupling loops, wherein said resonators of said second resonator group are stepped resonators; a plurality of frequency