The Administrative Court Organization Act Article 6

Each province, municipality, and special district shall have a High Administrative Court. However, for regions with a small jurisdiction or light work-load, one High Administrative Court may be shared among several provinces, municipalities, and special districts; for regions with a vast jurisdiction or heavy work load, the number of High Administrative Courts may be increased. The divisions or changes of jurisdiction areas of a High Administrative Court shall be prescribed by the Judicial Yuan.
中文原文 行政法院組織法第6條
省、直轄市及特別區域各設高等行政法院。
但其轄區狹小或事務較簡者,得合數省、市或特別區域設一高等行政法院,其轄區遼闊或事務較繁者,得增設之。
高等行政法院管轄區域之劃分或變更,由司法院定之。

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