Robert Downey Jr. has been cast as Tony Stark in Jon Favreau's Iron Man movie for Marvel Studios, Variety reported. The movie, based on the classic Marvel Comics character, is set for release by Paramount in May 2008. It will be the first to be self-financed by Marvel. Downey will play Stark, a wealthy industrialist who invents a high-tech suit of body armor that gives him super powers when he is kidnapped. In the comics, Stark was an alcoholic, a trait that will undoubtedly draw public comparisons with Downey's own struggles with substance abuse, the trade paper reported. But Marvel production president Kevin Feige told the trade paper that the first Iron Man movie won't deal with Stark's alcohol problems, though it would likely come up in potential sequels. The first film will deal with Stark's invention of the Iron Man suit and his conflicted past as a weapons inventor. Principal photography on "Iron Man" is set to begin in February.