The former leader, who was accused of laundering money, accepting bribes and committing forgery, has now been convicted of embezzling less money than previously assumed last year.
Chen’s wife saw her sentence decreased from life to 14 years in jail. But Chen said he would appeal.
The former president, who previously claimed his trial was revenge by his political enemies for his push for Taiwan independence from China, said that Friday’s ruling had given him “some hope”.
Legal experts said that if Chen’s sentence is upheld by the Supreme Court, he could be released in 10 years.
The court also slashed a 30-month jail sentence for the ex-president’s son Chen Chih-chung to 14 months, while cutting the 20-month sentence of his daughter-in-law Huang Jui-ching to one year.