A dielectric filter or a dielectric duplexer is provided which comprises a dielectric block in a substantially rectangular parallelepiped shape, having a pair of opposite parallel end-faces and plural sides extending between the paired opposite end-faces, one of the plural sides being a mounting face; plural resonator holes elongating through the inside of the dielectric block across the paired opposite end-faces; inner conductors provided on the inner walls of the plural resonator holes, respectively; an outer conductor provided on the outside of the dielectric block; input-output electrodes provided only on one of the paired opposite end-faces, separated from the outer conductor, and capacitance-coupled to the predetermined inner conductors, respectively; and conductive terminals for external connection, connected to the input-output electrodes, having at least portions thereof lying substantially in the same plane as the mounting face. In the dielectric filter or the dielectric duplexer, since input-output electrode are provided on the end-face of the dielectric block, not provided on the sides of the dielectric block, the deterioration of Q0, caused by the input-output electrodes, can be reduced. Accordingly, the insertion loss and the attenuation characteristics are improved.