Wash apples well. Carefully slice apples as thin as possible using a mandoline slicer or a sharp knife, discard seeds. Place slices on a parchment lined baking sheet. Generously brush with maple syrup.
Place in a 200F° oven for 3-4 hours or until apple chips are crisp.
If making multiple trays at once, be sure to rotate trays between racks after each hour. I made 2 trays on day one and 3 trays on day two.
Store in an airtight container for up to several weeks or more.