Assessment of the critical infrastructure (CI) criticality is an essential task in the task complex to ensure the protection of CI. The article shows the significant distinction between criticality assessment and risk assessment. Based on the concept of criticality, the paper presents the method to the categorization of CI and critical information infrastructure (CII) facilities, along with the developed procedure for identifying and categorizing CI and CII facilities. The presented method allows the development of cybersecurity procedures for various critical infrastructure facilities.