Copyright Act Article 30

Except as otherwise provided in this Act, economic rights endure for the life of the author and fifty years after the author's death.Where a work is first publicly released between the fortieth and fiftieth years after the author's death, the economic rights shall endure for a term of ten years beginning from the time of the first public release.
中文原文 著作權法第30條
著作財產權,除本法另有規定外,存續於著作人之生存期間及其死亡後五十年。
著作於著作人死亡後四十年至五十年間首次公開發表者,著作財產權之期間,自公開發表時起存續十年。

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