PURPOSE: To prevent the input-output leakage as well as a ghost phenomenon by providing a gap part to a printed wiring board set between input and output terminals of a filter element and at the same time masking a space part between the input and output.

CONSTITUTION: A gap part 154 is provided to a printed wiring board 150 set between input and output terminals 151 and 152 of a filter element 74. Then a shielding plate 155 is set orthogonally to a frame to mask a space part formed between the input and output of the element 74. The plate 155 consists of a shielding plate 155' at the case side and a shielding plate 155" at the terminal side. The plate 155' has a cut formed at the middle part and fitted to the case of the element 74 with such a size that secures contacts at both sides of the plate 155'. While the plate 155" has a size that secures contacts with the side faces of the frame and a partitioning plate. Then the case part of the element 74 is put into the cut part of the plate 155' with the plate 155" set between terminals 151 and 152. Thus the element 74 is held between plates 155' and 155".