This article is about criteria of reliability of information. The validity period of the information has been determined. It is established that an important stage of selection, development of methods and mechanisms for ensuring the reliability of information is the analysis of the processes of its processing. The definition of the information reliability assessment is given, and it is also established that the complexity of the information reliability assessment is information evaluation. To assess the accuracy of information, such features as the doubtfulness of the facts presented, the emotional coloring of the content, the tone of the content in relation to an object or event, the sensational content, the hidden content. These features will be based on monitoring the reliability of information in the information space, which aims to minimize the subjectivity of peer review of the content of authors from the point of view of their influential orientation towards individuals of the information space. In order to minimize this subjectivism, the basis of evaluations is the key criteria for the reliability of information, which, unlike estimates, are largely fully measured: the criterion of balance of information, the criterion for separating facts from opinions, the criterion for the accuracy and reliability of information, the criterion for completeness of information. Thus, there is a need to create an algorithm for assessing the reliability of information in the information space, which makes it possible to investigate information resources for the impact on them, identify problems of information security in a timely manner, recommend proven solutions for use at critical sites, organize and to carry out special trainings at the state level, etc.