A coil structure comprising: an inductor coil including a self-bonding wire and a central hole; a detection coil electromagnetically coupled to the inductor coil a support unit surrounding at least a portion of an outer periphery of the inductor coil; and a housing including an upper magnetic body and a lower magnetic body facing each other in a vertical direction with the inductor coil therebetween to form an inner space in which the inductor coil and the detection coil are provided, the upper magnetic body and the lower magnetic body each including a protrusion (31b, 32b) inserted into the central hole of the inductor coil, wherein each of the upper magnetic body and the lower magnetic body includes a flat plate (31a, 32a) in which the protrusion is provided in a center thereof, and a first edge structure (31c, 32c) and a second edge structure (31d, 32d) provided on respective sides of the protrusion and surrounding the protrusion, wherein the first edge structure and the second edge structure face each other in a first direction, and the housing includes an opening exposing the inner space to outside on both sides of the housing in a second direction crossing the first direction, wherein the support unit includes a bobbin including a support plate having a groove in a partial region and a pillar extending upwardly from a center of the support plate wherein a through hole is formed in centers of the support plate and the pillar, the inductor coil is provided on the support plate to surround the pillar, and the detection coil is inserted into the groove, and the lower magnetic body covers a lower surface of the support plate, the upper magnetic body covers an upper portion of the pillar and the inductor coil, and the protrusion of each of the lower magnetic body and the upper magnetic body is inserted into the through hole. an inductor coil including a self-bonding wire and a central hole; a detection coil electromagnetically coupled to the inductor coil a support unit surrounding at least a portion of an outer periphery of the inductor coil; and a housing including an upper magnetic body and a lower magnetic body facing each other in a vertical direction with the inductor coil therebetween to form an inner space in which the inductor coil and the detection coil are provided, the upper magnetic body and the lower magnetic body each including a protrusion (31b, 32b) inserted into the central hole of the inductor coil, wherein each of the upper magnetic body and the lower magnetic body includes a flat plate (31a, 32a) in which the protrusion is provided in a center thereof, and a first edge structure (31c, 32c) and a second edge structure (31d, 32d) provided on respective sides of the protrusion and surrounding the protrusion, wherein the first edge structure and the second edge structure face each other in a first direction, and the housing includes an opening exposing the inner space to outside on both sides of the housing in a second direction crossing the first direction, wherein the support unit includes a bobbin including a support plate having a groove in a partial region and a pillar extending upwardly from a center of the support plate wherein a through hole is formed in centers of the support plate and the pillar, the inductor coil is provided on the support plate to surround the pillar, and the detection coil is inserted into the groove, and the lower magnetic body covers a lower surface of the support plate, the upper magnetic body covers an upper portion of the pillar and the inductor coil, and the protrusion of each of the lower magnetic body and the upper magnetic body is inserted into the through hole.