A commutation type DC breaker comprising a main switch inserted in series into a main circuit for connecting a DC source and a load, a commutation capacitor, a reactor, and a commutation switch for supplying charges stored in the commutation capacitor to the main switch in an opposite direction to a main circuit current, producing a current zero point, thereby breaking the main switch, characterized in that the commutation capacitor, the reactor, and the commutation switch which are composed a commutation circuit and a control circuit for controlling the turning on or off of the main switch and the commutation switch are loaded on a frame with the main switch loaded.