A thermally actuated switching device, at least comprising a base body (2) provided with a back wall (21), an electric switch (10) and a spring-mounted actuating arm (3) for the switch (10) by transmitting an actuating movement, which arm (3) in the region of one end comprises a bent part (5) and a hinge axis (4), and the bent part (5) is able to connect with two clamping lips (27,28) supports, which are cut outs of the base wall (2) and of the back wall (21) and turned upwards to extend in a plane substantially parallel to the hinge axis (4). The base body (2,21) furthermore comprises one or more positioning elements (31,32), in which are inserted one or more projections (33,34) of the actuating arm (3), in order the latter to be secured in the direction of the hinge axis (4).