Juvenile Justice Act Article 71

A juvenile defendant may not be detained unless there are no alternatives.A juvenile defendant shall be detained in a juvenile detention center; once reaching twenty (20) years of age, he/she shall be sent to a detention center.The detention during investigation of a juvenile criminal matter by the juvenile court shall be deemed as detention before sentencing, to that Article 46 of the Criminal Code regarding sentence deduction shall apply mutatis mutandis.
中文原文 少年事件處理法第71條
少年被告非有不得已情形,不得羈押之。
少年被告應羈押於少年觀護所。
於年滿二十歲時,應移押於看守所。
少年刑事案件,前於法院調查及審理中之收容,視為未判決前之羈押,準用刑法第三十七條之二折抵刑期之規定。

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