<p>An indoor-use multi-cavity filter comprising a cavity (1) and a cover (2) arranged on the cavity. The cavity is provided therein with multiple resonant cavities (3). Each resonant cavity has arranged therein a resonant rod (4). The cover has arranged thereon a tuning screw (5). The cavity is made of a plastic material. The cavity has arranged on the bottom outer surface thereof a metal heat-dissipating plate (6). Each resonant rod is connected at the bottom thereof to the metal heat-dissipating plate. Each resonant rod has connected at the bottom thereof to a thermally conductive metal piece. The thermally conductive metal piece is connected at the bottom thereof to the metal heat-dissipating plate. The resonant rod and the thermally conductive metal piece are integrally formed. The thermally conductive metal piece penetrates the bottom face of the cavity to connect to the metal heat-dissipating plate. The thermally conductive metal piece and the metal heat-dissipating plate are connected via a connecting piece (10). The connecting piece penetrates the metal heat-dissipating plate from the bottom upwards to connect to the thermally conductive metal piece. The filter reduces heat accumulated within the plastic cavity, maintains great electrical performance, is easy to assemble and to manufacture, and reduces manufacturing costs.</p>
