Apple has sold nine million of its new iPhone models in three days.
The company said that sales of the iPhone 5S and 5C had beaten previous launches of new phones.
Apple said demand for the 5S had outstripped supply and Apple shares rose almost 6% on the news before falling back to trade 4% higher.
The 5S has a fingerprint sensor built into the phone's main button. The cheaper 5C comes with a plastic back in a choice of colours.
In a statement Tim Cook, Apple's chief executive said: "The demand for the new iPhones has been incredible, and while we've sold out of our initial supply of iPhone 5S, stores continue to receive new iPhone shipments regularly.
"We appreciate everyone's patience and are working hard to build enough new iPhones for everyone.