The boy, together with four other friends, was skiing off piste at the ski resort in Härjedalen when they happened to ski over the bear's lair.
The bear woke up from his winter-long slumber and dragged one of the boys down into the lair, according to Jämtland police.
"He was able to get out of the lair by himself," said Emma Ekdahl at Jämtland police.
The injured boy, who was bitten in both legs and was clawed on his back, was rushed to hospital in Östersund. The hospital announced on Friday evening that the boy was feeling okay considering the circumstances.
After attacking the boy, the bear then fled from the scene. The county administrative board in Jämtland was contacted and a conservationist was called to assess whether the bear could pose a danger to others.
It is very rare that people are attacked by bears, said Ole-Gunnar Stöen at research organisation the Scandinavian Brown Bear Research Project.
"When they are attacked it is most commonly in connection to a hunt," he said.
Ole-Gunnar Stöen said that the main reason why hunters are attacked is that they get too close to the winter lair and disturb the bear.