The purpose of the present study was to determine the relationship between teachers' emotions (pleasure, anxiety and anger) and immunity with instructional quality (cognitive activation, support for students and classroom management). The studied sample included 77 teachers and students according to Morgan's table and using available sampling method. The data collection tools were instructional quality questionnaire (Buric & Frenzel, 2021), teacher emotions questionnaire (Frenzel et al., 2016) and language teacher immunity questionnaire (Hiver, 2017). Multi-level structural equation modeling was used in data analysis. The findings of the research indicated that the immunity of the English language teacher and the quality of teaching are significantly influenced by the emotions of the teacher. There is a positive relationship between the two constructs of teacher's emotions and pleasure and a negative relationship with teacher's anxiety and anger. In addition, teacher immunity partially mediates the relationship between teacher emotions and teaching quality. The results showed that the positive relationship between happy English teachers and providing quality education and improving students' learning experiences highlights the need to strengthen the positive emotional experiences of language teachers and their psychological health.