A circuit breaker controller is mounted on each vehicle of an electric train together with a receiver that detects a track antenna beacon installed at a predetermined position before and after the dead section, to control a circuit breaker by detecting the track antenna beacon by the receiver. The circuit breaker controller includes a running-position calculation unit that calculates a running position of the vehicle based on a speed of the electric train, a circuit-breaker control-position calculation unit that calculates a circuit-breaker off-control position, and a circuit breaker control unit that executes off-control of the circuit breaker at a point in time at which the running position and the circuit-breaker off-control position match each other.