A circuit breaker (100, 200, 300, 400, 500, 600, 700) comprising: an inner conductor having a direction of extension; an outer conductor surrounding an outer circumference of the inner conductor with a spacing between the inner conductor and the outer conductor; a plurality of flexible conductors each having a first end connected to the outer circumference of the inner conductor and having flexibility, the first ends of the plurality of flexible conductors being spaced from each other in the direction of extension; a plurality of connection conductors provided inside the outer conductor and connected to second ends of the plurality of flexible conductors in one-to-one correspondence; a heat pipe connected to each of the plurality of connection conductors and drawn to outside of the outer conductor, the heat pipe containing refrigerant; and a radiator provided on an outer circumference of a portion of the heat pipe which is drawn to outside of the outer conductor, wherein the heat pipe includes an insulating hollow body located inside the outer conductor, and a portion of the heat pipe on an outer conductor side and a portion of the heat pipe on an inner conductor side are insulated from each other by the insulating hollow body and the heat pipe has a plurality of sections each connecting a corresponding one of the plurality of connection conductors to the insulating hollow body and the heat pipe further includes a communication path (154, 254) connecting portions of the heat pipe to each other to cause the plurality of sections to be in communication with each other, each of the portions being connected to a corresponding one of the plurality of connection conductors. an inner conductor having a direction of extension; an outer conductor surrounding an outer circumference of the inner conductor with a spacing between the inner conductor and the outer conductor; a plurality of flexible conductors each having a first end connected to the outer circumference of the inner conductor and having flexibility, the first ends of the plurality of flexible conductors being spaced from each other in the direction of extension; a plurality of connection conductors provided inside the outer conductor and connected to second ends of the plurality of flexible conductors in one-to-one correspondence; a heat pipe connected to each of the plurality of connection conductors and drawn to outside of the outer conductor, the heat pipe containing refrigerant; and a radiator provided on an outer circumference of a portion of the heat pipe which is drawn to outside of the outer conductor, wherein the heat pipe includes an insulating hollow body located inside the outer conductor, and a portion of the heat pipe on an outer conductor side and a portion of the heat pipe on an inner conductor side are insulated from each other by the insulating hollow body and the heat pipe has a plurality of sections each connecting a corresponding one of the plurality of connection conductors to the insulating hollow body and the heat pipe further includes a communication path (154, 254) connecting portions of the heat pipe to each other to cause the plurality of sections to be in communication with each other, each of the portions being connected to a corresponding one of the plurality of connection conductors.