Measuring the personal aspects of development is a challenge that researchers and practitioners are facing. Despite the fact that the results regarding the socio-emotional development of students are recorded in federal educational standards of Russia, there is neither a theoretical framework suitable for assessing these results, nor re- liable measuring materials suitable for its monitoring assessment. This paper is aimed to develop a monitoring tool to estimate social and emotional skills of secondary-school students. The results of a field test were analysed using Item Response Theory (IRT). Construct validity, reliability, differential item functioning and other characteristics were checked. Psychometric properties of the tool as well as theoretical framework are presented. The tool has good psychometric quality and can be used to assess the development of social and emotional skills of adolescents.