Introduction: This paper aims at describing the psychometric features of the Achievement Emotions Questionnaire (AEQ), focusing specifically on the section that measures class emotions. From a theoretical perspective, this instrument was designed based on the control-value theory of achievement emotions. Therefore, a description of the psychometric features of the questionnaire could pave the way for discussions about the underlying theory. From a practical perspective, it is important to highlight that there is no documented literature in our country about the technical advantages and benefits that the instrument has. Thus, the description of the instrument could represent important contributions to the field. Method: The section of the AEQ that assesses class emotions consists of 80 items grouped into eight scales: enjoyment, hope, pride, anger, anxiety, shame, hopelessness, and boredom. We based the reliability analysis on the responses obtained from a sample of 450 students who attend the School of Engineering at Universidad Nacional de Río Cuarto (Argentina). For the analysis of content validity, we considered 11 experts' responses to a questionnaire specifically designed to this end. Results: The results obtained indicate acceptable reliability levels both for the use of the questionnaire as a whole and also for the individual use of each scale, except for "hope," for which future analysis and reformulations are needed. The inter-rater reliability test allowed us to confirm the content validity of the instrument, as 80-100% of the raters showed agreement in indicating high or moderate relevance for 79 of the 80 items in the questionnaire. Conclusion: The reliability and validity indices obtained in this study provide evidence to conclude that the Argentinean Spanish version of the Achievement Emotions Questionnaire (AEQe) can be used reliably with groups of students in our context. In addition, the results suggest alternatives that could increase the levels of reliability and validity obtained in this study.