A film deposition apparatus includes a rotary table having a substrate placement area to support a substrate, a vacuum container including a container and a top panel, an open-and-close mechanism configured to open and close the top panel, reactant gas nozzles disposed through and supported by an outer wall of the container to be situated at different angular positions with respect to a rotation center of the rotary table to face areas in which the substrate placement area passes, the reactant gas nozzles having gas discharge ports arranged in radial directions to supply respective reactant gases to the wafer thereby to form respective process areas, a discharge gas supply unit situated at an angular position between the process areas to supply purge gas to form an isolation area that isolates atmospheres of the process areas from each other, and an exhaustion unit configured to exhaust atmosphere inside the vacuum container.