If you mean that round, later triangle, advice in his chest, it is a so-called arc reactor. The round one was made with palladium (which in Iron Man 2 poisoned his body so he replaced it), the triangle one with an element that Tony "re-discovered" (I am not quite sure about the name though).
Arc Reactor
49
10880 Malibu Point
booze, hubris, Immortus, captain America
you go to either the Pokemon center or a mans house in olivine and he will give it to you
Arc Reactor
iron nan is a nanny its iron mans nanny
Whats iron mans quest?
No a woman's heart beats faster than a mans
no they are not
49
they use magic
throw a mans belly
Chuck Norris does iron mans stunts
Tony stark
10880 Malibu Point
Yes