The purpose of this study is to understand the process of change in teacher identity by exploring the identity crisis and overcoming process experienced by high-experienced English teachers in secondary schools due to their age and the characteristics of the subject of English. For this purpose, in this study, through interviews with three middle school teachers with more than 25 years of experience as an English teacher, how they perceive themselves as an English teacher, what kind of crisis they have experienced as a highly experienced English teacher, and how they overcame it. According to the results of the study, all of the high-experienced English teachers had pride and confidence as English teachers, but as “high-experienced” teachers, they experienced cut off communication with students, physical problems, and limitations in acquiring new knowledge and skills. In addition, as highly experienced teachers in ‘English’, they felt a sense of crisis due to problems in adapting to changing class trends, pronunciation problems, and responding to students’ gaps in English level. However, highly experienced English teachers tried to overcome this identity crisis in various ways, and through this, they continued to grow and develop as teachers. Based on these research results, this study found that teacher identity is not fixed, but in a continuous process of constant change and development. In addition, it was discussed that high-experienced teachers not only experience the downward path of retirement through professional setbacks and stagnation, but that they can move on to the upward path of professional growth and development through efforts to overcome the frustration.