Connection terminal and circuit interruption device

There is provided a connection terminal and a circuit breaker device, which is provided with this connection terminal. A plate-shaped second bus bar (19) is welded on a metal (23) having a low melting point to a conductive Thermitgehause (26). The bus bar (19) has an opening (20) which is adapted to fix a terminal-provided body line by a screw fixing, and a thin portion (51) between the opening (20) and the metal (23) is formed and has a plate thickness that is smaller than the plate thickness of the other portions of the bus bar (19). The thin portion (51) is provided with wedge-shaped notches (53). When a screw is attached, which has been inserted in a clockwise or counter-clockwise into the opening (20), resulting from the rotational load through the thin plate (51) and the paired notches (53) is absorbed. Thanks to the absorption, it is therefore possible to limit a transfer of the load to the welded portion of the metal (23), which has a low melting point.