The Levitron™ is put into action by spinning the top on the plastic plate on top of the box. By lifting the plastic plate, the top is raised into the air. The plastic is quickly pulled out from under the top. If the top is just the right distance from the magnet in the box, the top will spin in the air.
The Levitron™ appears to float in the air because the two magnets are repelling each other. The "top" magnet is stabilized in the air by the spinning action of the top. As the top slows down it becomes unstable and begins to wobble like an ordinary top. Eventually it flips over.