PURPOSE: To improve the filter effect and to attain high circuit integration by arranging plural filter elements employing a magnetic bead in a conventional package form and sealing them in a magnetic compound to form a compound.

CONSTITUTION: Plural magnetic beads 2 are arranged on a line and a magnetic compound 3 is formed in a cube compound. The noise attenuation factor of the magnetic bead is shown in a curve A and that of the magnetic compound 3 is illustrated in a curve B as shown in a frequency versus attenuation characteristic diagram. The total attenuation factor is shown in a curve C in broken lines and both the width and attenuation factor of the frequency band are both improved in comparison with the attenuation characteristic curve A of each individual filter element based on the compound formation comprising the magnetic compound 3. Through the filter constitution above, the mount space is made more compact than that of a single device filter.