A substrate processing apparatus for processing a substrate comprises: a plurality of chuck pins each having an accommodating groove for accommodating a portion of peripheral part of the substrate, holding the substrate at a hold position in a horizontal posture by pressing inner faces of the accommodating grooves toward portions of peripheral part of the substrate; and a plurality of guide members, being disposed on or above the respective plurality of chuck pins, guiding process liquid discharged from the substrate to a surrounding area of the substrate; wherein each of the plurality of guide member includes: an inner-edge guide disposed at a position inward and above the accommodating groove; and an outer-edge guide disposed at a position level with or below the inner-edge guide and outward the chuck pin.