An inherently fail-safe processing or control apparatus, having a first processing unit with a first data processor and/or controller; at least one input port for input data received from at least oneremote unit; at least one output port for output data to be transmitted to at least one remote unit. According to the invention, the first processing unit comprises means for generating an unique code for functional control of the processing and/or receiving and/or transmitting steps being performed and a port for the transmission of the generated checkwords. A functional checker and protection unit is further provided, which consists of a second inherently fail-safe processing unit, which executes a program for checking the functional steps of the first processing unit and a program for checking the correctness of functional control codes and the time sequence thereof. The checker and protection unit communicates with the first processing unit and generates signals for enabling it when checkwords are correct, and signals for disabling the first processing unit and/or for forcing the transmission of predetermined output data for fail-safe remote unit control, or generates itself predetermined output data for fail-safe remote unit control and/or enables/disables vital functions of the remote unit and/or of the first processing unit.