A film deposition apparatus comprises: a vacuum chamber; a cylindrical target, a circumferential surface of the target being opposite to a substrate, and the target being disposed in the vacuum chamber so as to intersect a conveyance direction of the substrate; a driving unit configured to rotatively drive the target; a magnetic field creator disposed inside the target; a reactive gas flow unit configured to flow a reactive gas, the reactive gas flow unit being disposed in the vicinity of the target; an optical emission monitor configured to monitor an optical emission intensity of plasma at a location between the substrate and the target and in the vicinity of the target; and a controlling unit configured to control a rotation speed of the target driven by the driving unit, such that the optical emission intensity monitored by the optical emission monitor approaches a preset target optical emission intensity.