The location of the position and the treatment liquid nozzle of the outer periphery of the rotating substrate by a spin chuck is detected by the position detection unit. The amplitude of the time variation of the position of the outer peripheral part of the substrate which is detected during the rotation of the substrate is obtained as the amplitude of the first. It is off the spin-chuck the center of rotation also in parallel to the rotating direction of the substrate, at the same frequency as the spin chuck rotation frequency by the relative position of the treatment liquid nozzle for the spin chuck to the positioning part are also periodically changes the amplitude of the first . Of the treatment liquid phase of the time variation of the time position of the outer peripheral portion of the substrate and the phase of the change in the position of the nozzle the difference is below a pre-determined value by the position adjusting section. Then, the treatment liquid is ejected to the periphery of the rotating substrate from the treatment liquid nozzle.