An arc path forming unit, comprising: a magnet frame having an inner space, and comprising a plurality of surfaces surrounding the inner space; and magnets coupled to the plurality of surfaces to form magnetic fields in the inner space, wherein the plurality of surfaces comprise: a first surface extending in one direction; and a second surface disposed to face the first surface and extending in the one direction, wherein the magnets comprise: a first magnet disposed on one of the first surface and the second surface; a second magnet disposed on another one of the first surface and the second surface; a third magnet disposed on the another surface with being spaced apart from the second magnet by a predetermined distance; and a fourth magnet disposed on the another surface between the second magnet and the third magnet, and wherein a first facing surface of the first magnet facing the another surface has a polarity equal to a polarity of a fourth facing surface of the fourth magnet facing the one surface, and has a polarity different from a polarity of a second facing surface of the second magnet and a third facing surface of the third magnet both facing the one surface, wherein the first magnet, the second magnet, the third magnet, and the fourth magnet extend in the one direction, wherein the first magnet extends longer than the second magnet, the third magnet, and the fourth magnet, wherein the first magnet overlaps the fourth magnet along a longitudinal direction, and wherein the first magnet partially overlaps the second magnet and the third magnet along the longitudinal direction. a magnet frame having an inner space, and comprising a plurality of surfaces surrounding the inner space; and magnets coupled to the plurality of surfaces to form magnetic fields in the inner space, wherein the plurality of surfaces comprise: a first surface extending in one direction; and a second surface disposed to face the first surface and extending in the one direction, wherein the magnets comprise: a first magnet disposed on one of the first surface and the second surface; a second magnet disposed on another one of the first surface and the second surface; a third magnet disposed on the another surface with being spaced apart from the second magnet by a predetermined distance; and a fourth magnet disposed on the another surface between the second magnet and the third magnet, and wherein a first facing surface of the first magnet facing the another surface has a polarity equal to a polarity of a fourth facing surface of the fourth magnet facing the one surface, and has a polarity different from a polarity of a second facing surface of the second magnet and a third facing surface of the third magnet both facing the one surface, wherein the first magnet, the second magnet, the third magnet, and the fourth magnet extend in the one direction, wherein the first magnet extends longer than the second magnet, the third magnet, and the fourth magnet, wherein the first magnet overlaps the fourth magnet along a longitudinal direction, and wherein the first magnet partially overlaps the second magnet and the third magnet along the longitudinal direction. a first surface extending in one direction; and a second surface disposed to face the first surface and extending in the one direction, wherein the magnets comprise: a first magnet disposed on one of the first surface and the second surface; a second magnet disposed on another one of the first surface and the second surface; a third magnet disposed on the another surface with being spaced apart from the second magnet by a predetermined distance; and a fourth magnet disposed on the another surface between the second magnet and the third magnet, and wherein a first facing surface of the first magnet facing the another surface has a polarity equal to a polarity of a fourth facing surface of the fourth magnet facing the one surface, and has a polarity different from a polarity of a second facing surface of the second magnet and a third facing surface of the third magnet both facing the one surface, wherein the first magnet, the second magnet, the third magnet, and the fourth magnet extend in the one direction, wherein the first magnet extends longer than the second magnet, the third magnet, and the fourth magnet, wherein the first magnet overlaps the fourth magnet along a longitudinal direction, and wherein the first magnet partially overlaps the second magnet and the third magnet along the longitudinal direction. a first magnet disposed on one of the first surface and the second surface; a second magnet disposed on another one of the first surface and the second surface; a third magnet disposed on the another surface with being spaced apart from the second magnet by a predetermined distance; and a fourth magnet disposed on the another surface between the second magnet and the third magnet, and wherein a first facing surface of the first magnet facing the another surface has a polarity equal to a polarity of a fourth facing surface of the fourth magnet facing the one surface, and has a polarity different from a polarity of a second facing surface of the second magnet and a third facing surface of the third magnet both facing the one surface, wherein the first magnet, the second magnet, the third magnet, and the fourth magnet extend in the one direction, wherein the first magnet extends longer than the second magnet, the third magnet, and the fourth magnet, wherein the first magnet overlaps the fourth magnet along a longitudinal direction, and wherein the first magnet partially overlaps the second magnet and the third magnet along the longitudinal direction.