It depends. The stake helps the tree grow straight. If the trunk seems sturdy already, you can remove the stake. Young trees might still be rather flexible and could benefit from the stake being left on for another growing season, especially if planted in a windy area. For topiaries such as spirals, if the stake is taller than the tree, it might be beneficial to leave it in for continued training.
The stake should NOT be left on forever. Make sure the ties aren’t restricting the growth of the trunk. If they have gotten tight, remove them immediately. If continued staking is needed, attach the stake with new ties.