Abstract: A miniaturized plug-in cutout/switch is controlled by a push-button (1) and comprises a connection and disconnection mechanism using a captive ball (4d) circulating in a track cage (4a), having two positions selected by successive applications of pressure to the push-button (1) corresponding to the switch connected and switch disconnected states. The cutout/switch includes an independent locking mechanism for a movable contacts (11) which is operated by a bimetallic strip (8) which triggers the opening of the contacts when a current overload occurs in the protected circuit. The simple design of the apparatus permits a miniaturized construction which is particularly advantageous for its use on panels where small dimensions and the rationalization of its shapes make it suitable, for example on aircraft panels.