Apple claims to have sold three million iPads in the 80 days since the device was launched on 3 April.
That is up one million in the 20 days since Apple began selling the iPad in UK, Australia, Canada, France, Germany, Italy, Japan, Spain and Switzerland.
The European release was delayed for a month after unexpectedly high demand in the US, where Apple said it sold 500,000 iPads in the first week.
"People are loving iPad as it becomes a part of their daily lives," said Steve Jobs, Apple's chief executive.
Developers have created more than 11,000 applications for the iPad that take advantage of its Multi-Touch user interface, large screen and high-quality graphics.
The iPad will run almost all of the more than 225,000 applications available in the Apple App Store, including apps already purchased for the iPhone and iPod touch.
Apple plans to roll out the iPad to nine more countries in July, while the rest of the world will have to wait until later in the year.