The invention provides a
circuit breaker, which at least comprises an insulating shell and internal elements, the internal elements at least comprise an arc extinguish chamber, a static contact, a moving contact, a wiring terminal, an operating mechanism and an arc striking sheet, the arc extinguish chamber is formed by superposing a plurality of
metal arc extinguishing grid sheets, and the arc striking sheet and the static contact are integrally arranged. The connecting conductor between the static contact and the wiring terminal is provided with at least one
magnet yoke, the
magnet yoke is U-shaped or U-shaped, and the opening of the
magnet yoke faces the
metal arc extinguishing grid sheet or / and the arc striking sheet of the arc extinguishing chamber. When current passes through the connecting conductor, a
magnetic field can be generated at the opening of the magnet yoke, and the
magnetic field acts on the
metal arc extinguishing grid sheet or / and the arc striking sheet to quickly attract an
electric arc so as to promote the
electric arc to quickly jump; when the moving contact leaves the static contact and generates an
electric arc, the metal arc extinguishing grid piece or / and the arc striking piece with the
magnetic field accelerates the electric arc generated on the static contact to move towards the metal arc extinguishing grid piece or / and the arc striking piece, and the electric arc deionization effect is improved.