US Patent 7612640 Magnetic element

To provide a magnetic element the ends of the coil of which can be drawn out from the core easily, is compact, and further, is one in which magnetic saturation does not arise easily. A magnetic element has a core unit provided with a wound coil, a center core 105 inserted into the interior of the inner periphery of the coil, planar cores disposed at both ends of the center core, and a side core disposed between the planar cores and on the outside periphery of the coil. The side core is disposed so as to form an open portion between the two planar cores around the coil, with a recessed portion formed in a surface of the side core facing the coil in which the coil is partially contained.