NOVELTY - A substrate processing apparatus (1) comprises a substrate holding unit that holds a substrate; and a mixed liquid supply unit (4) including a first tank in which a processing liquid to be supplied to the substrate and a flow path for the processing liquid leading from first tank to substrate, where mixed liquid supply unit raises a temperature of a mixed liquid containing phosphoric acid, sulfuric acid, and water by supplying phosphoric acid, sulfuric acid and water to the flow path and by mixing a liquid containing sulfuric acid and a liquid containing water in the flow path.    USE - As a substrate processing apparatus for processing substrate (claimed) such as semiconductor wafers, substrates for liquid crystal displays, substrates for plasma displays, substrates for field emission displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells.    ADVANTAGE - The substrate processing apparatus is capable of restraining or preventing a fall in temperature of a processing liquid that is supplied to substrates.    DETAILED DESCRIPTION - A substrate processing apparatus (1) that processes a substrate by a mixed liquid containing phosphoric acid, sulfuric acid, and water, comprises a substrate holding unit that holds a substrate; and a mixed liquid supply unit (4) including a first tank in which a processing liquid to be supplied to the substrate held by the substrate holding unit is stored and a flow path for the processing liquid leading from the first tank to the substrate held by the substrate holding unit, where the mixed liquid supply unit raises a temperature of a mixed liquid containing phosphoric acid, sulfuric acid, and water by supplying the phosphoric acid, the sulfuric acid, and the water to the flow path and by mixing a liquid containing the sulfuric acid and a liquid containing the water in the flow path, the mixed liquid supply unit supplying a mixed liquid containing a phosphoric acid aqueous solution whose temperature is close to its boiling point to the substrate. An INDEPENDENT CLAIM is included for substrate processing method of processing a substrate by a mixed liquid containing phosphoric acid, sulfuric acid, and water, involving temperature raising step of raising a temperature of a mixed liquid containing phosphoric acid, sulfuric acid, and water by supplying the phosphoric acid, the sulfuric acid, and the water to a flow path for a processing liquid leading from a first tank, in which the processing liquid to be supplied to a substrate is stored, to the substrate and by mixing a liquid containing the sulfuric acid and a liquid containing the water in the flow path; and a mixed liquid supply step of supplying a mixed liquid that has been generated in the temperature raising step and that contains a phosphoric acid aqueous solution whose temperature is close to its boiling point to the substrate.    DESCRIPTION OF DRAWING(S) - The figure shows view of structure of a substrate processing apparatus.    Apparatus (1)    Processing liquid supply unit (3)    Mixed liquid supply unit (4)    Controller (5)