A circuit breaker comprising: a case; a fixed contact mounted within the case; a moving contact rotatably mounted on the case to be brought into contact with or separated from the fixed contact; and a switching mechanism that generates a driving force (F 1, F 1 ', F 2, F 2 ') to rotate the moving contact, the switching mechanism comprising a linkage with a first rocker that is mounted to be rotatable around a first rotation axis by the driving force (F 1, F 1 ', F 2, F 2 '), wherein, during the ON operation, an axis formed by the first rotation axis and the point of action of the driving force (F 1, F 1 ', F 2, F2') makes an acute angle with the line of action of the driving force (F 1, F 1 ', F 2, F 2 '), so that the first rocker causes the tangential force (A 1, A 1 ', A 2, A 2 ') at the circumference of the point of action of the driving force (F 1, F 1 ', F 2, F 2 ') to act as input load, at least one hinge part of the linkage is configured in a way that a connecting pin is movably hinged to a long hole-shaped hinge hole, and during the ON operation, at least one hinge part of the linkage causes the tangential force (A 1, A 1 ') to increase by changes in the acute angle as the connecting pin moves from a first side of the long hole-shaped hinge hole to a second side, whereby the linkage further comprises: a trip latch, one end of which is hinged to the inside of the case and the other end of which is held by a latch holder; characterised by one end of said first rocker being hinged to the trip latch by the first rotation axis; a second rocker spaced away from the first rocker, one end of which is hinged to the case by a second rotation axis, the second rocker comprising the long hole-shaped hinge hole at the other end, and a connecting link, wherein one end of the connecting link is hinged to the other end of the first rocker by a first pin and the other end of the connecting link is hinged to the other end of the second rocker by the connecting pin, the connecting link being hinged to the long hole-shaped second rocker hinge hole. a case; a fixed contact mounted within the case; a moving contact rotatably mounted on the case to be brought into contact with or separated from the fixed contact; and a switching mechanism that generates a driving force (F 1, F 1 ', F 2, F 2 ') to rotate the moving contact, the switching mechanism comprising a linkage with a first rocker that is mounted to be rotatable around a first rotation axis by the driving force (F 1, F 1 ', F 2, F 2 '), wherein, during the ON operation, an axis formed by the first rotation axis and the point of action of the driving force (F 1, F 1 ', F 2, F2') makes an acute angle with the line of action of the driving force (F 1, F 1 ', F 2, F 2 '), so that the first rocker causes the tangential force (A 1, A 1 ', A 2, A 2 ') at the circumference of the point of action of the driving force (F 1, F 1 ', F 2, F 2 ') to act as input load, at least one hinge part of the linkage is configured in a way that a connecting pin is movably hinged to a long hole-shaped hinge hole, and during the ON operation, at least one hinge part of the linkage causes the tangential force (A 1, A 1 ') to increase by changes in the acute angle as the connecting pin moves from a first side of the long hole-shaped hinge hole to a second side, whereby the linkage further comprises: a trip latch, one end of which is hinged to the inside of the case and the other end of which is held by a latch holder; characterised by one end of said first rocker being hinged to the trip latch by the first rotation axis; a second rocker spaced away from the first rocker, one end of which is hinged to the case by a second rotation axis, the second rocker comprising the long hole-shaped hinge hole at the other end, and a connecting link, wherein one end of the connecting link is hinged to the other end of the first rocker by a first pin and the other end of the connecting link is hinged to the other end of the second rocker by the connecting pin, the connecting link being hinged to the long hole-shaped second rocker hinge hole. a trip latch, one end of which is hinged to the inside of the case and the other end of which is held by a latch holder; characterised by one end of said first rocker being hinged to the trip latch by the first rotation axis; a second rocker spaced away from the first rocker, one end of which is hinged to the case by a second rotation axis, the second rocker comprising the long hole-shaped hinge hole at the other end, and a connecting link, wherein one end of the connecting link is hinged to the other end of the first rocker by a first pin and the other end of the connecting link is hinged to the other end of the second rocker by the connecting pin, the connecting link being hinged to the long hole-shaped second rocker hinge hole.