A multi-mode filter for realizing wide-band is disclosed. The multi-mode filter includes a housing; a plurality of cavities formed in the housing; a plurality of resonators located in each of the cavities; at least one connector formed through a side wall of the housing; and at least one coupling element connected to the at least one connector in the cavities, the at least one coupling element coupling the at least one connector with at least one of the resonators respectively, wherein each of the at least one coupling element has “T” shape in view of front section and “L” shape in view of side section.