PURPOSE: To miniaturize the whole filter by arranging an electric shield means between plural strip conductors and connecting the shield means with an earth pattern via a via hole formed in a dielectric.

CONSTITUTION: A via hole 25 is formed by making a lower part conductor 2 and an upper part conductor 4 penetrate between strip conductors 5 and 6. Within the via hole 25, a conducting bar 26 is inserted. The via hole 25 and the conducting bar 26 are composed of groups 29 and 30 arranged at a constant space and the conducting bar 26 is connected with earth patterns 1 and 3, respectively. Thus, the conducting bar 26 performs its electric shield role between the conductors 5 and 6. Therefore, the coupling distance ID between the conductors 5 and 6 can be reduced, a coupling width IC can be increased and the whole filter can be miniaturized.