Regulations Governing Licences and Ratings for Airmen Article 13

The age of applicants for Aircraft pilot rating license shall meet the following requirements:(1) Applicants for student pilots shall not be less than 18 years of age.(2) Applicants for private pilot licence shall not be less than 18 years of age.(3) Applicants for commercial pilot licence shall not be less than 18 years of age.(4) Applicants for multi-crew pilot shall not be less than 18 years of age.(5) Applicants for airline transport pilot shall not be less than 21 years of age.(6) Except for Flight Simulation Flight simulation training device Training Device instructors, applicants for flight instructor shall not be less than 23 years of age or over 65 years of age.When performing flight operations, the age of Commercial pilot licence holders, multi-crew pilot licence holders and airline transport pilot licence holders shall not be more than 65 years of age.Pilots engaged in international civil air transport operations who are older than 60 years of age shall not engage in single-pilot operations.
中文原文 航空人員檢定給證管理規則第13條
航空器駕駛員申請檢定之年齡應符合下列各款規定:
一、學習駕駛員應年滿十八歲。
二、自用駕駛員應年滿十八歲。
三、商用駕駛員應年滿十八歲。
四、多組員飛機駕駛員應年滿十八歲。
五、民航運輸駕駛員應年滿二十一歲。
六、飛航教師應年滿二十三歲,最高不得逾六十五歲。
但為飛航模擬訓練設備教學者,不在此限。
商用駕駛員、多組員飛機駕駛員及民航運輸駕駛員執行飛航任務時,不得逾六十五歲。
民用航空運輸業國際航線之駕駛員,年逾六十歲者不得從事單一駕駛員飛航任務。

English translation for reference only; the Chinese text prevails. Not legal advice.