A method of discriminating a state of a sputtering apparatus in which, by sputtering a target, a film is formed on a substrate disposed to lie opposite to the target, the discrimination being made, prior to the film formation on the substrate, as to whether an atmosphere in the vacuum chamber is in a state fit for film formation. As the sputtering apparatus, use is made of one provided inside the vacuum chamber with an isolated space which is isolated from the vacuum chamber by an isolating means (6, 71˜73), the isolated space being for the target and the substrate to lie therein opposite to each other, the sputtering apparatus being so arranged that the isolated space is evacuated accompanied by the evacuation in the vacuum chamber. The vacuum chamber is evacuated to a predetermined set pressure and a gas is introduced therein in this state.