PURPOSE: To form an LC filter with ease of manufacture while reducing number of components by providing an insulating layer to a cylindrical ferrite member made of a garnet type ferrite.

CONSTITUTION: The LC filter 11 is provided with the cylindrical ferrite member 13 made of a garnet type ferrite expressed in R3Fe3O12 and a through-conductor 12 inserted into a through-part of the member 13. A silver electrode 15 is formed to an outer peripheral face of the member 13 with baking. The insulating layer 13a is formed to the outer peripheral of the member 13 by baking the electrode. The insulating layer 13a provides a capacitance and the remaining part 13b of the member 13 provides an inductance and the LC filter is formed between the through-conductor 12 and the electrode 15. As a result, since the number of components is decreased, the LC filter with ease of maunfacture is formed.