The main aim of this work is refer to a negative impact on the state regulation based on the theory of natural monopoly. It is based on history and criticism of this theory mentioned in works of economists of the Chicago school. First of all it observes the present effort about deregulation of gas and than it observes changes of opinions in the theory and experiences in network sector. It analyzes business environment of the Slovak gas industry, event argue that the new rule on market does not brought any expected competition. Indicate on input barrier into gas environment, however also seeks to found the way into longed competition of gas market