The substrate processing apparatus includes a processing chamber including an outer chamber configured to hold a processing liquid and an inner chamber capable of surrounding the substrate held by the substrate holder; a liquid delivery pipe having one end coupled to a bottom of the inner chamber and other end coupled to the outer chamber; a pump configured to suck the processing liquid from the inner chamber through the liquid delivery pipe and to deliver the processing liquid to the outer chamber through the liquid delivery pipe; and a guide cover having a through-hole in which the substrate holder can be inserted. The guide cover is located below an upper end of the outer chamber and above the inner chamber.