A DC current breaker for breaking a DC current at the time of occurrence of an accident, comprising: a main conduction unit including a close/open switch, a protection switch, and a commutate switch which are high-speed mechanical switches and are connected in series to each other in this order on a main conduction path where a current is flowed in a normal operation state, the protection switch protecting the commutate switch, and the close/open switch finally breaking a flow of a current of the main conduction unit; a power semiconductor switch connected in parallel to the commutate switch; a capacitor connected in parallel to the commutate switch and the protection switch; and a surge arrester connected in parallel to the capacitor wherein the commutate switch is a monostable switch, the commutate switch receives a trip signal of the DC current breaker to start an opening operation and after a time point when the current of the main conduction unit is completely commutated to the capacitor, the commutate switch automatically returns to a closed state and an opening response characteristic of the commutate switch is faster than opening response characteristics of the protection switch and the close/open switch, so that an arc voltage is more speedily increased than those of the protection switch and the close/open switch, wherein the DC current breaker further comprises a discharge unit for discharging a voltage charged in the capacitor after a DC current breaking operation is finally finished by the close/open switch and wherein the discharge unit is configured to include a discharge switch and a discharge resistor which are connected in series to each other on a discharge path connected in parallel to the capacitor. a main conduction unit including a close/open switch, a protection switch, and a commutate switch which are high-speed mechanical switches and are connected in series to each other in this order on a main conduction path where a current is flowed in a normal operation state, the protection switch protecting the commutate switch, and the close/open switch finally breaking a flow of a current of the main conduction unit; a power semiconductor switch connected in parallel to the commutate switch; a capacitor connected in parallel to the commutate switch and the protection switch; and a surge arrester connected in parallel to the capacitor wherein the commutate switch is a monostable switch, the commutate switch receives a trip signal of the DC current breaker to start an opening operation and after a time point when the current of the main conduction unit is completely commutated to the capacitor, the commutate switch automatically returns to a closed state and an opening response characteristic of the commutate switch is faster than opening response characteristics of the protection switch and the close/open switch, so that an arc voltage is more speedily increased than those of the protection switch and the close/open switch, wherein the DC current breaker further comprises a discharge unit for discharging a voltage charged in the capacitor after a DC current breaking operation is finally finished by the close/open switch and wherein the discharge unit is configured to include a discharge switch and a discharge resistor which are connected in series to each other on a discharge path connected in parallel to the capacitor.