A method of processing a for an electronic device, comprising, at least: a nitridation step (a) of supplying nitrogen radicals on the surface of the electronic device substrate, to thereby form a nitride film on the surface thereof; and a hydrogenation step (b) of supplying hydrogen radicals to the surface of the electronic device substrate. By use of this method, it is possible to recover the degradation in the electric property of an insulating film due to a turnaround phenomenon which can occur at the time of nitriding an Si substrate, etc.