Preheat oven to 400 degrees F. lightly coated baking sheet with non-stick cooking spray.
Slice the sweet potatoes by hand in very thin slices, or use a food processor with a 2-millimeter disk. In a large bowl, carefully toss the sweet potato slices by hand in the oil to coat the chips lightly.
Lay the slices in a single layer in the prepared baking pan. Bake the chips for fifteen minutes.
Turn each piece over with a metal spatula and bake for five more minutes. Chips should be dry and slightly crisp. If not, bake up to three more minutes, checking every minute so the chips won’t burn.