Preheat air fryer to 400°F. Pat roast dry. Season with salt, pepper, garlic powder, and rosemary.
Spray tray with cooking spray and air fry the prime rib at 400°F for 8 minutes.
Lower to 300°F. Cook for 70 minutes, checking every 20 minutes using a meat thermometer.
Remove and cover with foil. Let it rest for 15 minutes before slicing.
After resting, slice with your best carving knife, serve, and enjoy!