A low-voltage circuit breaker that comprises: a containment structure; a control mechanism; a plurality of circuit breaking poles, chosen between a first type of pole that comprises a first housing containing a first fixed contact and a corresponding first moving contact that can be coupled to said first fixed contact by means of its rotation around a point, and a second type of pole that comprises a second housing containing a second fixed contact and a corresponding second moving contact that can be coupled to said second fixed contact by means of a translatory movement along an axis; a first kinematic coupling between said control mechanism and said first moving contact, in the case of said poles belonging to said first type of pole, or a second kinematic coupling between said control mechanism and said second moving contact, in the case of said poles belonging to said second type of pole.