A coil component unit, comprising: a pair of cores being arranged in parallel so that the axial directions of the pair of cores extend in parallel to each other; and a pair of coils wound around each of the pair of cores, wherein each of the pair of cores is configured to include a plurality of split cores arranged linearly alongside each other in an axial-center direction of the coil wound around the core, wherein the split cores are each formed into an annular shape, wherein an axial direction of each of the split cores aligns with the axial-center direction of the coil, so as to form the core into a hollow cylindrical shape having a hollow portion, wherein an intervening layer made out of a non-magnetic material is disposed between split cores adjacent to each other of the plurality of split cores, the coil component unit further comprising: a pair of holding members arranged one on each side in the axial-center direction of the pair of cores, wherein each of the holding members comprises respective insertion holes, and a pair of fastening members fastening the pair of holding members to each other, wherein the pair of fastening members comprises each a bolt, each bolt being inserted into a respective insertion hole of said holding members and passing through said hollow portions of a respective one of the pair of cores, wherein a respective nut is tightened at the tip end side of a respective one of the bolts so as to sandwich both ends of the pair of cores by the pair of holding members such that the plurality of split cores have been made in a state in pressure contact with each other, characterized in that a flat plate-like partitioning plate is disposed between the pair of cores, both ends of the partitioning plate each being provided with a cutout-shaped portion, and wherein said pair of holding members are disposed so as to penetrate through a plate surface of the partitioning plate through the respective cutout-shaped portions. a pair of cores being arranged in parallel so that the axial directions of the pair of cores extend in parallel to each other; and a pair of coils wound around each of the pair of cores, wherein each of the pair of cores is configured to include a plurality of split cores arranged linearly alongside each other in an axial-center direction of the coil wound around the core, wherein the split cores are each formed into an annular shape, wherein an axial direction of each of the split cores aligns with the axial-center direction of the coil, so as to form the core into a hollow cylindrical shape having a hollow portion, wherein an intervening layer made out of a non-magnetic material is disposed between split cores adjacent to each other of the plurality of split cores, the coil component unit further comprising: a pair of holding members arranged one on each side in the axial-center direction of the pair of cores, wherein each of the holding members comprises respective insertion holes, and a pair of fastening members fastening the pair of holding members to each other, a pair of holding members arranged one on each side in the axial-center direction of the pair of cores, wherein each of the holding members comprises respective insertion holes, and a pair of fastening members fastening the pair of holding members to each other, wherein the pair of fastening members comprises each a bolt, each bolt being inserted into a respective insertion hole of said holding members and passing through said hollow portions of a respective one of the pair of cores, wherein a respective nut is tightened at the tip end side of a respective one of the bolts so as to sandwich both ends of the pair of cores by the pair of holding members such that the plurality of split cores have been made in a state in pressure contact with each other, characterized in that a flat plate-like partitioning plate is disposed between the pair of cores, both ends of the partitioning plate each being provided with a cutout-shaped portion, and wherein said pair of holding members are disposed so as to penetrate through a plate surface of the partitioning plate through the respective cutout-shaped portions.