In a DC circuit breaker device, first and second semiconductor switches are connected in series on a main circuit line such that current-carrying directions of the switches are opposite to each other. A first diode is connected in anti-parallel with the first semiconductor switch, and a second diode is connected in anti-parallel with the second semiconductor switch. First and second mechanical circuit breakers are connected in series with each other and in parallel with the whole of the first and semiconductor switches. First and second backward current generation circuits are connected in series with each other and in parallel with the whole of the first and second mechanical circuit breakers. An injection switch is connected between a node between the first and second mechanical circuit breakers and a node between the first and second backward current generation circuits.