Administrative Procedure Act Article 39

Where it is necessary for the purpose of inquisition into facts and evidence, an administrative authority may give any related person a written notification, requiring that he appear to give his opinions.The notification shall give such details as the purpose of the inquiry, the time and place where the person notified is required to appear, whether or not he is allowed to appoint another person to appear on his behalf, and the consequence for failure to appear.
中文原文 行政程序法第39條
行政機關基於調查事實及證據之必要,得以書面通知相關之人陳述意見。
通知書中應記載詢問目的、時間、地點、得否委託他人到場及不到場所生之效果。

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