PURPOSE: To facilitate the automatic assembling step while miniaprinted coils having conductive patterns are laminated, a core passing through the central part of the conductor patterns is provided and then the conductor patterns of respective printed coils are electrically connected.

CONSTITUTION: Flat plate coils 50a-50c are provided with the same core inserting holes 51 and conductor patterns 52. The core inserting holes 51 are provided in the two positions on respective flat plate 50a-50c so as to insert both leg parts of a core 20. Besides, two each of the conductor patterns 52 are provided with the core inserting holes 51 centered on the eddy winding while terminals 53-54 are provided on both ends of the eddy winding. Next, the input terminal 53, the interlayer connecting terminal 54 and an output terminal 55 are electrically connected. Through these procedures, two coils magnetically junctioned with each other by the core 20 are composed of the flat plate coils 50 to be equivalently turned into six turn line filter. Furthermore, the line filter can be manufactured by laminating the flat plate coils 5 and fitting the core 20 to the core inserting holes 51 thereby enabling the automatic assembling step to be facilitated.