A Direct Current circuit breaker using a magnetic field, comprising: a main switch installed on a DC line; a coil wound to produce a magnetic flux in a direction perpendicular to a direction of an arc current generated when the main switch is opened; a semiconductor switch configured to switch application of current to the coil; a capacitor connected in series with the semiconductor switch; and a first diode configured to enable current in the line, supplied from a first end of the main switch, to be transferred to the capacitor, wherein when a short-circuit fault in the DC line occurs, the semiconductor switch is turned on so that the current is applied to the coil using a voltage charged in the capacitor, wherein, when the fault occurs in a state in which the capacitor is charged, the main switch is opened, and the semiconductor switch is turned on, so that the current is supplied to the coil through the semiconductor switch using a voltage charged in the capacitor, and a magnetic flux is produced in a direction perpendicular to a direction of an arc current generated in the main switch using the current supplied to the coil, thus increasing a resistance to the arc current, wherein, in a state in which the semiconductor switch is turned on, current in the DC line is returned to the coil through the first diode and the semiconductor switch, thus continuously increasing the resistance to the arc current. a main switch installed on a DC line; a coil wound to produce a magnetic flux in a direction perpendicular to a direction of an arc current generated when the main switch is opened; a semiconductor switch configured to switch application of current to the coil; a capacitor connected in series with the semiconductor switch; and a first diode configured to enable current in the line, supplied from a first end of the main switch, to be transferred to the capacitor, wherein when a short-circuit fault in the DC line occurs, the semiconductor switch is turned on so that the current is applied to the coil using a voltage charged in the capacitor, wherein, when the fault occurs in a state in which the capacitor is charged, the main switch is opened, and the semiconductor switch is turned on, so that the current is supplied to the coil through the semiconductor switch using a voltage charged in the capacitor, and a magnetic flux is produced in a direction perpendicular to a direction of an arc current generated in the main switch using the current supplied to the coil, thus increasing a resistance to the arc current, wherein, in a state in which the semiconductor switch is turned on, current in the DC line is returned to the coil through the first diode and the semiconductor switch, thus continuously increasing the resistance to the arc current. wherein, when the fault occurs in a state in which the capacitor is charged, the main switch is opened, and the semiconductor switch is turned on, so that the current is supplied to the coil through the semiconductor switch using a voltage charged in the capacitor, and a magnetic flux is produced in a direction perpendicular to a direction of an arc current generated in the main switch using the current supplied to the coil, thus increasing a resistance to the arc current, wherein, in a state in which the semiconductor switch is turned on, current in the DC line is returned to the coil through the first diode and the semiconductor switch, thus continuously increasing the resistance to the arc current.