To provide a breaker with excellent reliability even through the structure is especially simple.

The breaker comprises a causing 10, a first conductor 14, a second conductor 16, a position adjusting element 12, and a separating element 22. The conductors 14 and 16 extend into the casing 10, and are in contact with each other at contact positions 18 and 20. The position adjusting element 12 can adjust the position between a start position and a separated position. When the separating element 22 is located at the separated position, the first conductor 14 and the second conductor 16 are separated from each other.