Abstract: A circuit breaker includes a fixed contact having a fixed contact point; a movable contact having a movable contact point contacting with the fixed contact point; and an arc extinguishing device housed in a main body case. In the arc extinguishing device, a plurality of magnetic grids, each having a pair of grid leg portions, is disposed in layer form, and an arc generated between the fixed contact point and the movable contact point at a time of an opening operation is drawn into the magnetic grids and extinguished. A magnetic flux is generated between the pairs of grid leg portions configuring the arc extinguishing device in a direction perpendicular to the arc generated between the fixed contact point and the movable contact point, and permanent magnets and a permanent magnet holding member are disposed therein.