Abstract. The article presents the results of studies of the errors of electronic tacheometers in field conditions and improvement of their accuracy. In modern metrology of geodetic instruments, a pressing issue is the research and development of new methods for calibrating inclinometers or calibration stands. Since the unit for measuring angles in electronic tacheometers is a separate working part, a regulatory document has been developed for this purpose for specialists and organizations working in the field of geodesy, cartography and cadastre, developing methods and improving activities related to their research. Attention is focused on the need to perform high-precision geodetic measurements of horizontal angles, taking into account the study of tools and equipment.