A breaker includes a stationary contact, a movable contact, an operation device including a link portion liked to the movable contact and including an output lever rotatably supported, the operation device operating rotation of the output lever in accordance with a first control signal for a command for pulling out the movable contact and a second control signal for a command for inserting the movable contact, and an auxiliary contact to switch between turn-on and turn-off of an input of the first control signal and the second control signal to the operation device in conjunction with operation of the output lever, the auxiliary contact being able to be used in a circuit configuration to monitor a state of the operation device. The output lever rotates so as to operate a first link portion on a side toward a first direction with respect to a rotational center of the output lever.