Start by washing your apple thoroughly. Then, using a sharp knife, slice the apple into thin rounds, about 1/8 inch thick. Removing the core is optional; it depends on your preference.
Place the apple slices in a mixing bowl. Sprinkle cinnamon over the apple slices according to your taste preference. Toss gently to ensure each slice is evenly coated.
Lay the apple slices in a single layer in the air fryer basket. Make sure not to overcrowd them; you may need to cook in batches.
Set your air fryer to 300°F (150°C) and cook the apple slices for 15-20 minutes. Halfway through, shake the basket to ensure even cooking. Keep a close eye on them to prevent burning.
Once the apple chips are golden and crispy, remove them from the air fryer and let them cool on a baking sheet for a few minutes. Enjoy them right away or store for later!