Reactive sputtering method and device

The present invention provides a method for reactive sputtering in which a reactive sputtering apparatus including a sputtering vaporization source provided with a metal target disposed in a vacuum chamber , a sputtering power source to drive the sputtering vaporization source , and an introduction mechanism to introduce an inert gas for sputtering and a reaction gas for forming a compound with sputtered metal into the vacuum chamber is used, and reactive sputtering film formation is performed on a substrate disposed in the above-described vacuum chamber, wherein the method includes the steps of performing constant-voltage control to control the voltage of the above-described sputtering power source at a target voltage Vs and, in addition, performing target voltage control at a control speed lower than the speed of the above-described constant-voltage control, the target voltage control operating the above-described target voltage Vs in order that the spectrum of plasma emission generated forward of the above-described sputtering vaporization source becomes a target value.