The present invention relates to a slimmable magnetic element and a circuit board including the same. An EMI filter according to one embodiment includes a core unit including an upper core and a lower core, and a coil unit partially disposed within the core unit and including a first coil unit and a second coil unit, wherein the first coil unit includes a first substrate, a first upper conductive pattern disposed on an upper surface of the first substrate, and a first lower conductive pattern disposed on a bottom surface of the first substrate, and the second coil unit includes a second substrate, a second upper conductive pattern disposed on an upper surface of the second substrate, and a second lower conductive pattern disposed on the bottom surface of the second substrate, and the coil unit includes the first upper conductive pattern, the first lower conductive pattern, and the second upper conductive pattern. a primary pattern lead-out portion disposed on one side of the central portion, where one ends of the first upper conductive pattern and the first lower conductive pattern are led out from the central portion; and a second pattern lead-out portion disposed on the other side of the central portion, where one ends of the second upper conductive pattern and the second lower conductive pattern are led out from the central portion, and within the second pattern lead-out portion, the second upper conductive pattern and the second lower conductive pattern may be overlapped in a vertical direction so that at least a portion of the second upper conductive pattern and the second lower conductive pattern intersect on a plane.