The work is devoted to solving the problem of monitoring and diagnostics of the complex technical and technological objects state by data-based models application. As an example of these models use, the process of electrochemical dimensional processing of high-strength materials was considered. The models of electrochemical processing based on neural networks are developed. The option for introduction of the developed models in the control system of electrochemical machining machines with the use of the Fault Detection and Identification method is proposed. The experimental results have shown that the developed models can reproduce the real process of electrochemical treatment and may be used for the tasks of diagnostics of the state of technological electrochemical processing.