The questions of improvement of research competences of a school teacher are considered. The competences of a teacher-researcher are interpreted as developing professional and personal properties with a complex structure, the elements of which are focused on the implementation of the functions of the research activities of a school teacher; they are integral and integrative; they contribute to self-development of a teacher in the chosen field of activity and the realization of his / her potential; form conditions to search for new information required in the resolution of difficult situations at a specific school according to the goals and objectives of the contemporary general education. The relevance of this article is associated with the increasing requirements imposed by society to the research activities of a modern school teacher. Areas of application of professional efforts are defined, where the research potential of a teacher is manifested most actively: the area of analysis, synthesis and mastering innovative pedagogical experience; field of popularization and initial practical use of innovative pedagogical experience and advanced developments; area of improvement of professional skills and disclosure of the creative potential of a teacher; area of innovative processes in the education system. Four levels of development of the research competences available to the school teacher are established: basic, empirical (locally-initiative), productive (tactical) and constructive (strategic) for which different degree of development of research competences is characteristic. The technology of improving the research competences of a school teacher is proposed, which includes four stages: motivational-target, theoretical, design, practical, control and remedial.