Hanging a chair from your ceiling can be safe if done correctly.
It all comes down to your ceiling structure and whether it can support the weight of the chair and the person using it.
You can't hang your chair from anywhere in your ceiling; you need to look for the strongest point.
You should attach the chair to a load-bearing ceiling joist or beam for optimal stability.
If you are unsure about ceiling joists and strength, consult a professional or consider using a hanging chair with a standalone frame instead, like the Habitat Malta Double Steel Hanging Chair.
Better to be safe than sorry!