Prison Act Article 3

Inmates sentenced to imprisonment, short-term imprisonment, or labor services commuted from a fine shall be housed in prison unless otherwise stipulated by law.An inmate sentenced to short-term imprisonment or labor services commuted from a fine shall be housed separately from those sentenced to imprisonment.
中文原文 監獄行刑法第3條
處徒刑、拘役及罰金易服勞役之受刑人,除法律另有規定外,於監獄內執行之。
處拘役及罰金易服勞役者,應與處徒刑者分別監禁。

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