Аннотация:The article considers the legal meaning of the notion of energy security taking into account the energy interests of various states, outlines and analyses the main components of energy security and the state’s role in their ensuring. It also studies the legal fundamentals of energy security at the level of the European Union and the Eurasian Economic Union, as well as the sources of national legal regulation with Germany and Russia taken as examples. Among the main components of energy security, one can distinguish, inter alia, the proper technical condition of the energy infrastructure and ensuring of the reliability of its functioning (including its accident-free operation and security), the availability of an amount of energy (energy resources) of appropriate quality at any time sufficient to satisfy the existing demand, affordable consumer prices, and the compliance of the energy supply and the operations in the sphere of energy with the environmental requirements and standards. Studying the role of the state in ensuring energy security, the author notes that the state uses both the methods of public law and those of private law and concludes that the role of the state in ensuring energy supply security consists, on the one hand, in forecasting of demand and supply, ensuring of favorable environment for the energy companies’ operation, regulation, state monitoring (surveillance), energy (energy resources) quality regulation, and implementation of the state energy policy, and, on the other hand, in influencing directly the energy (energy resources) production using the private law methods by way of holding stakes in the authorized (share) capital of energy companies and participating in corporate decisions making. Based on the research findings, a range of proposals has been formed, particularly, on the necessity to define the notion “energy security” in the laws in effect, and the author’s definition of the notion is suggested.