A low-voltage circuit breaker with interchangeable poles

A low-voltage circuit breaker that comprises: a containment structure (2); a control mechanism (3); a plurality of circuit breaking poles (4), chosen between a first type of pole (40) that comprises a first housing (41) containing a first fixed contact (42) and a corresponding first moving contact (43) that can be coupled to said first fixed contact by means of its rotation around a point (45), and a second type of pole (50) that comprises a second housing (51) 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 (55); a first kinematic coupling (6) between said control mechanism (3) and said first moving contact, in the case of said poles belonging to said first type of pole (40), or a second kinematic coupling (7) between said control mechanism and said second moving contact, in the case of said poles belonging to said second type of pole (50).