Abstract: A device for ATM cell switching having failure tolerance. The device is divided into two types of equipment modules. The first type includes connecting modules while the second type includes two branching and managing modules, one operating in an active mode while the other operates in a passive mode. An accessing device is implanted in each connector. Devices to execute the ATM layer function are almost identically implanted in each connector and in each of the two branching and managing modules. A supervision bus connects both types of modules to ensure quick and automatic reconfiguration of the device in case of failure in one of its components. The supervising bus is of simple configuration and only serves to carry, under the control of the managing module, signals indicative of the master and slave managing means as well as a signal indicative of the active branching module.