A wireless power transmission device comprising: a first coil; and a second coil electromagnetically coupled with the first coil without contacting therewith, wherein at least a portion of one of the first coil and the second coil passes through at least a portion of a space defined by the other of the first coil and the second coil; the wireless power transmission device further comprising: a first magnetic core disposed inside or outside the first coil and forming a first coil assembly together with the first coil; and a second magnetic core disposed inside or outside the second coil and forming a second coil assembly together with the second coil, wherein the second coil assembly passes through the first coil assembly via the space without contacting therewith; and wherein the first coil comprises a first portion and a second portion opposite to the first portion; and the space is a space defined between the first portion and the second portion of the first coil; and wherein the first magnetic core comprises: a U-shaped body portion; a first block connected to a side of the U-shaped body portion at an opening thereof; and a second block connected to the other side of the U-shaped body portion at the opening thereof; and wherein the first portion of the first coil is wound around the first block of the first magnetic core, and the second portion of the first coil is wound around the second block of the first magnetic core. a first coil; and a second coil electromagnetically coupled with the first coil without contacting therewith, wherein at least a portion of one of the first coil and the second coil passes through at least a portion of a space defined by the other of the first coil and the second coil; the wireless power transmission device further comprising: a first magnetic core disposed inside or outside the first coil and forming a first coil assembly together with the first coil; and a second magnetic core disposed inside or outside the second coil and forming a second coil assembly together with the second coil, wherein the second coil assembly passes through the first coil assembly via the space without contacting therewith; and wherein the first coil comprises a first portion and a second portion opposite to the first portion; and the space is a space defined between the first portion and the second portion of the first coil; and wherein the first magnetic core comprises: a U-shaped body portion; a first block connected to a side of the U-shaped body portion at an opening thereof; and a second block connected to the other side of the U-shaped body portion at the opening thereof; and wherein the first portion of the first coil is wound around the first block of the first magnetic core, and the second portion of the first coil is wound around the second block of the first magnetic core. a first magnetic core disposed inside or outside the first coil and forming a first coil assembly together with the first coil; and a second magnetic core disposed inside or outside the second coil and forming a second coil assembly together with the second coil, wherein the second coil assembly passes through the first coil assembly via the space without contacting therewith; and wherein the first coil comprises a first portion and a second portion opposite to the first portion; and the space is a space defined between the first portion and the second portion of the first coil; and wherein the first magnetic core comprises: a U-shaped body portion; a first block connected to a side of the U-shaped body portion at an opening thereof; and a second block connected to the other side of the U-shaped body portion at the opening thereof; and wherein the first portion of the first coil is wound around the first block of the first magnetic core, and the second portion of the first coil is wound around the second block of the first magnetic core. a U-shaped body portion; a first block connected to a side of the U-shaped body portion at an opening thereof; and a second block connected to the other side of the U-shaped body portion at the opening thereof; and wherein the first portion of the first coil is wound around the first block of the first magnetic core, and the second portion of the first coil is wound around the second block of the first magnetic core.