A magnetic core includes a first core having a recess and a second core, which has a first end portion and a second end portion both held in contact with the first core and forms a closed magnetic path with the first core. The second core is formed of material having a lower magnetic permeability and a higher saturation magnetic flux density than those of the first core. The second end portion includes a distal surface having an area larger than the cross-sectional area of the first end portion in a direction perpendicular to the direction in which a magnetic flux flows in the closed magnetic path. The distal surface of the second end portion is held in contact with the first core and the first end portion is engaged with the recess in the first core.