PURPOSE: To ensure high-frequency characteristics without requiring other parts, and to obtain an easily assembled excellent ultra-high frequency filter by grounding a leaf spring-shaped grounding protrusion formed between the input terminal and output terminal of housing to the ground plane of a printed board.

CONSTITUTION: One or more of leaf spring-shaped grounding protrusions 5 are projected between the input terminal 2 and output terminal 2 of a housing 3, and the leaf spring-shaped grounding protrusions 5 are grounded to the ground plane of a printed board 4. Protrusions can also be attached through point welding as the spring-shaped grounding protrusions 5, but cutting to a U shape through press molding of a surface oppositely faced to the printed board 4 of a filter housing 3 and erecting to the outside are of advantage at the points of the accuracy of finishing and working cost. Consequently, positive grounding is enabled among the grounding protrusions and the grounding pattern of the printed board, thus easily improving the electrical characteristics of a filter. A hole for a ground terminal need not be bored to the printed board mounted particularly, thus facilitating high density mounting when a multilayer board is used.