A converter using a planar transformer includes an input device that receives a first voltage, a transformer including a first planar transformer and a second planar transformer that reduce the first voltage, and an output device that outputs the first voltage as a second voltage, wherein the first voltage is greater than the second voltage, and the input device provides a current to a primary winding coil of each of the first planar transformer and the second planar transformer through a first current path and a second current path in which current directions are different with each other, and includes a plurality of inductors connected in parallel with the primary winding coil of each of the first planar transformer and the second planar transformer.