Abstract:Background and Objectives: Psychological state of a person can change under conditions of cognitive load. Excessive cognitive load can lead to distress, which reduces performance. Diagnosis of changes in the psychophysical state in the process of performing cognitive tasks is important for human health and increasing the efficiency of his work. Therefore, the purpose of the study is to develop a hardware and software complex for diagnosing the psychophysiological state of a person in the process of solving cognitive problems. Materials and Methods: Electroencephalogram signals were recorded using a developed device and a certified standard recorder during a biological experiment. A comparison was made of the diagnostic capabilities of the developed hardware-software complex and a serial device. Results: A hardware-software complex has been developed for diagnosing the psychophysiological state of a person in the process of solving cognitive problems using an electroencephalogram signal. The developed system has shown sensitivity and specificity values close to those of the serial recorder. Using the developed complex, the electroencephalogram channels suitable for diagnosing the psychophysical state have been selected. Conclusion: The developed hardware-software complex can be used to diagnose the psychophysiological state of a person in the process of performing cognitive tasks.