To prevent the resin soln. discharged on the inner periphery of the front of a disk substrate and that dropped on the outer periphery from being infiltrated into the rear by rotating the disk substrate at a high speed and moving a nozzle from outer periphery of the substrate to the outside thereof while uniformly applying the protective film forming resin soln.

When a nozzle 22 is placed above the front of a disk substrate 10, the substrate 10 is rotated at a high speed and uniformly coated. Even if a resin soln. 21 is leaked from the nozzle 22 and dropped, the soln. is centrifugally swept away and not infiltrated into the rear. Further, the suction force of a suck-back valve 25 is lowered due to an increase in the viscosity of the UV setting resin soln. 21. Consequently, even if the soln. is dropped on the outer periphery of the substrate 10 when the nozzle 22 is mixed, the dropped soln. is centrifugally swept away, since the substrate 10 is rotated at a high speed, and the soln. is never infiltrated into the rear of the substrate 10.