Iron Man is an action-adventure film based on the comic book superhero, Iron Man. Iron Man is the alter ego of billionaire playboy Tony Stark, played by Robert Downey, Jr. Tony Stark is the head of Stark Industries, a huge conglomerate defense contractor. Stark is also a brilliant man and his company has developed many state-of-the-art weapons. Stark heads to Afghanistan to demonstrate the company's latest missile to Army commanders over there. While he is there, he is injured by shrapnel from a bomb. Stark cannot get the shrapnel out of his chest so he puts an electromagnet there to protect himself. The electromagnet ends up giving him special powers.
While he was injured, Stark and another man, Yinsen, were captured by enemy forces. Yinsen helps Stark build a reactor to power the electromagnet and the man also build a protective suit that Stark can wear. The enemy discovers what the men are doing and try to stop them. Stark manages to power up the suit and escape but Yinsen is killed. Before he dies, Yinsen tells Stark that he must lead a life of purpose. Stark returns to Stark Industries headquarters in New York where he makes the decision to halt the production of all weapons. He decides that from now on Stark Industries will only built technology that helps in the peace process.
Stark finds out from a reporter that the companies old weapons were sold to the enemy forces in Afghanistan and are now being used to attack Yinsen's village. Stark is furious and he puts on his suit, transforming himself into Iron Man. He then heads overseas to stop the carnage. He is forced to reveal his identity to the Army commander so he is not shot. After the battle, Stark has his assistant Pepper Potts hack into the company computer to find out if any other weapons have been sold to the enemy. Pepper discovers that Stane, a vice president at Stark Industries, has been secretly supplying the terrorists and is planning to ruin Stark and takeover the company. Stane then ambushes Stark at home in at attempt to steal his reactor and suit. Stark and Stane begin to battle ferociously over the suit. Stark tricks Stane into standing under the reactor which explodes and causes him to die. Stark is victorious and he decides to tell the public that he is Iron Man. He does so in a press conference at the end of the film.