Singer Kim Jang-hoon was fined for smoking on board a Korea-bound plane from France, the court said Sunday.
The Incheon District Court handed down a fine of 1 million won (S$1200) against the 50-year-old singer for violating the domestic aviation safety law. He would otherwise have to complete 10 days of manual labour, the court said.
Kim was indicted in January after smoking a cigarette on Dec. 15 in the lavatory of a Korean Air plane bound for Incheon from Paris.
During police questioning, Kim reportedly said he smoked due to a panic disorder and stress after his scheduled performance was cancelled.
The prosecution did not put Kim on trial as he was a first-time offender and apologised immediately after being caught.
"Nothing can be an excuse for what I did. I am really sorry," he said in a public apology posted on his Facebook a few days later.
Kim has long been known for his good deeds and donations, worth more than 10 billion won so far, to poor students and children.
He has also been actively engaged in social movements, campaigning for Korea's sovereignty over the islets of Dokdo.