Introduction. Intensive and global changes in the education system that have occurred in recent years, the conditions of digitalization and convergence of education, changes in value orientations and a decrease in interest in learning among the younger generation place ever-increasing demands on the professional competencies of teachers and the development of their personal qualities. One of the significant ways that can significantly improve the professionalism of teachers and improve the quality of education in general is methodical support for the process of eliminating professional deficits of teachers based on informal education. Based on the above, the purpose of this article is to develop and substantiate the main approaches to organizing methodical work to eliminate deficiencies in the professional training of teachers based on informal education.Materials and Methods. The research was carried out by analyzing scientific literature on the research problem, analyzing regulatory sources, and summarizing our own practical experience on this topic. Studying the scientific literature on this topic, the history of the formation of the methodical service in Russia, the current state of methodological work in general education, and the results of an empirical study aimed at assessing the methodical competence of general education teachers were analyzed. Research methods: analysis of theoretical and regulatory literature, historiographic analysis, generalization, formulation of conclusions, analysis of practical experience, questionnaires, method of expert assessments.Results. To summarize the above, the generalized characteristics of the methodological service during the period of its modernization can be described as internally contradictory. On the one hand, the processes of humanization of education contributed to the revelation of the creative potential of talented teachers, who at that time created a number of original schools, enriching pedagogy with a number of new approaches to teaching and upbringing, new methods and technologies of teaching. The results of the study, confirming the presence of deficiencies in certain components of professional training of teachers, have updated the task of finding measures to solve pressing problems for the regional education system. The competency improvement project developed for these purposes was based on the use of informal education.Discussion and Conclusions. A condition for the effective implementation of methodical work by means of informal education is the formation of a digital educational environment, which provides the opportunity to diagnose the professional competencies of a teacher and develop personalized learning trajectories based on diagnosis. Informal education of a teacher should be implemented in formalized organizational and managerial conditions that make it possible to track the individual dynamics of the teacher, identify areas of his professional difficulties, and provide expert support if necessary.
