The Surface looks similar to the iPad - launched in 2010 - but has a more cinematic screen ratio.
The device also features an optional slimline tactile keyboard built into the tablet's case, as opposed to a standard touch keyboard.
There are two versions of the Microsoft Surface - one powered by an Intel (NasdaqGS: INTC - news) Ivy Bridge chipset for a "full windows experience" and a thinner, lighter but less powerful Windows RT version.
The Windows RT tablet is 9.3mm thin, weighs 680g and has a 10.6inch (27cm) display and built-in stand, while the more powerful version has the same display, is 13.5mm thick, weighs 860g and supports the high-speed USB 3 interface.
Both have front and rear-facing cameras.
The more powerful version of the Surface will run the latest Windows 8 Pro operating system.
Both have what Microsoft described as a unique vapor-deposited (PVD) magnesium case, with the Windows RT version coming with 32 or 64GB of memory, and the Intel version coming with 64 or 128GB.
The more powerful Intel version also features "digital ink" handwriting support through a pen that magnetises to the case.
Steven Sinofsky, president of Microsoft's Windows division, called the device a "tablet that's a great PC - a PC that's a great tablet".
No details on pricing were mentioned, except that it would be "comparable" with current ARM tablets and Intel-powered Ultrabooks.
"Microsoft founders Bill Gates and Paul Allen made a big bet - a bet on software - but it was always clear that we had to push hardware in ways that sometimes manufacturers hadn't envisioned," Microsoft CEO Steve Ballmer said at Monday's launch event.
"We believe that any intersection between human and machine can be made better when all aspects, hardware and software, are working together."
Launching its own tablet potentially throws Microsoft (EUREX: MSTF.EX - news) - which has much more experience as a software than a hardware company - into direct competition with its closest hardware partners such as Samsung and Hewlett-Packard.
It is hardly surprising Microsoft wants a piece of the tablet market - sales of the devices are expected to triple in the next two years, topping 180 million a year in 2013, easily outpacing growth in the flatlining traditional PC market.
Apple has sold 67 million iPads since the device's launch.
Apple, which makes both hardware and software for greater control over the performance of the final product, has revolutionised mobile markets with the launch of the iPhone and then the iPad.
Largely thanks to the iPod, iPhone and iPad, Apple's stock became more valuable than Microsoft in 2010. It is now worth twice as much as its old enemy.
But the search engine monolith splashed out on phone maker Motorola Mobility earlier this year for $12.5bn, so it may be only a matter of time until it announces a tablet of its own.