The textbook contains a systematic presentation of the fundamentals of econometrics and is written on the basis of lectures that the authors gave for a number of years at the Russian School of Economics and the Higher School of Economics. Linear regression models are studied in detail (least squares method, hypothesis testing, heteroscedasticity, autocorrelation of errors, model specification). Separate chapters are devoted to systems of simultaneous equations, the maximum likelihood method in regression models, models with discrete and limited dependent variables. Three new chapters have been added to the sixth edition of the book. The chapter on "Panel Data" expands the book to a comprehensive list of topics traditionally included in modern basic econometrics courses. Chapters “Preliminary Testing” and “Econometrics of Financial Markets” have also been added, which will be useful for those interested in the theoretical and applied aspects of econometrics, respectively. The number of exercises has been significantly increased. Includes exercises with real data, available to the reader on the book’s website. For undergraduates, graduate students, teachers, as well as specialists in applied economics and finance