The Moscow City Court released Adamov after changing his jail term to a suspended sentence after just two months in custody.
Adamov returned to his post of scientific adviser at the Dollezhal Institute, one of Russia's largest nuclear research centers, where he has worked for around 20 years.
"I came to the institute yesterday and spent the whole day there today. Science is my life, and this cannot be changed. I intend to continue my scientific activities," Adamov told RIA Novosti.
Adamov was charged with leading a criminal group that embezzled some $110 million from Russia's state budget and other state enterprises and organizations. The verdict, which was announced in February, when the ex-minister was arrested in the courtroom, had not come into full legal force yet.
Adamov's lawyers earlier said the prosecution had failed to provide any evidence to substantiate the defendant's guilt, and said the sentence was too severe.
Adamov, 69, who served from 1998 to 2001 as Russia's nuclear energy minister, was originally arrested in Switzerland in May 2005 at the request of the United States, where he was accused of misappropriating $9 million allocated to Russia for nuclear safety projects.
The ex-minister was extradited to Russia in early 2006 to face an investigation into large-scale fraud and abuse of office charges and subsequent trial and was released on bail in July 2006 on condition he did not leave the country.
Charges against Adamov are still pending in the U.S.
