School and classroom climate refers to the quality of academic, managerial, social and emotional interactions between classmates and between students and teachers. According to research results, the climate in the classroom and its subjective perception by students have a significant impact on the behavior and academic performance, psychological well-being, the development of character and giftedness of schoolchildren. The article presents the results of standardization of the questionnaire "Classroom climate" – a modification of the Russian version of the questionnaire "School climate". The study sample consisted of 2543 students of schools in the Central Federal District of the RF – 45.0% (N = 1145) males, 55.0% (N = 1397) females, of which 875 (34.4%) schoolchildren in grades 5-6, 752 (29.6%) – 7-8 grades, 916 (36.0%) – 9-10 grades. The structure of the questionnaire included six scales identified by the factor analysis method (principal component analysis, Varimax rotation with Kaiser normalization): scale 1 “Supportive teacher”, scale 2 “Cooperation with classmates”, scale 3 “Organization of work in the classroom”, scale 4 “Rivalry with classmates”, scale 5 “Pressing school environment” and scale 6 “Classmates’ involvement in studies”. The construct validity of the questionnaire was statistically proven. Confirmatory factor analysis showed a satisfactory agreement between the empirical data and the structure of the questionnaire. The scales correlate with each other at an average level, the directions of the connections correspond to the expected ones. The internal reliability of all scales was statistically confirmed using the Cronbach's Alpha coefficient. The convergent validity of the corresponding scales of the Classroom Climate questionnaire was confirmed by correlations with the scales of the Phillips School Anxiety Test, the Dembo – Rubinstein self-assessment methodology, as well as the average academic performance for the year. All correlations are moderate and weak, but theoretically expected and explainable. Differential validity was statistically proved. The questionnaire can be recommended to school psychologists for use in the practice of psychological and pedagogical support for different groups of schoolchildren in order to monitor and support strategies aimed at creating favorable conditions for the development of students.