A film deposition apparatus comprising: a process chamber inside which a reduced pressure space is maintained; a gas supplying portion that supplies a film deposition gas to the process chamber; a substrate holding portion that is made of a material including carbon as a primary constituent and holds a substrate in the process chamber; a coil that is arranged outside the process chamber and inductively heats the substrate holding portion; and a thermal insulation member that covers the substrate holding portion, characterized in that the film deposition apparatus further comprises: a gas line to supply to the process chamber a cooling gas for cooling the process chamber; a thermal insulation member holding structure, formed outside the thermal insulation member in order to cover the thermal insulation member to separate the reduced pressure space of the process chamber into a film deposition gas supplying space to which the film deposition gas is supplied and a thermal insulation space to which the cooling gas is supplied, the thermal insulation member holding structure holding the thermal insulation member separated from the process chamber to form the thermal insulation space defined between the process chamber and the thermal insulation member holding structure. a process chamber inside which a reduced pressure space is maintained; a gas supplying portion that supplies a film deposition gas to the process chamber; a substrate holding portion that is made of a material including carbon as a primary constituent and holds a substrate in the process chamber; a coil that is arranged outside the process chamber and inductively heats the substrate holding portion; and a thermal insulation member that covers the substrate holding portion, a thermal insulation member that covers the substrate holding portion, characterized in that the film deposition apparatus further comprises: a gas line to supply to the process chamber a cooling gas for cooling the process chamber; a thermal insulation member holding structure, formed outside the thermal insulation member in order to cover the thermal insulation member to separate the reduced pressure space of the process chamber into a film deposition gas supplying space to which the film deposition gas is supplied and a thermal insulation space to which the cooling gas is supplied, the thermal insulation member holding structure holding the thermal insulation member separated from the process chamber to form the thermal insulation space defined between the process chamber and the thermal insulation member holding structure. the film deposition apparatus further comprises: a gas line to supply to the process chamber a cooling gas for cooling the process chamber; a thermal insulation member holding structure, formed outside the thermal insulation member in order to cover the thermal insulation member to separate the reduced pressure space of the process chamber into a film deposition gas supplying space to which the film deposition gas is supplied and a thermal insulation space to which the cooling gas is supplied, the thermal insulation member holding structure holding the thermal insulation member separated from the process chamber to form the thermal insulation space defined between the process chamber and the thermal insulation member holding structure. a gas line to supply to the process chamber a cooling gas for cooling the process chamber; a thermal insulation member holding structure, formed outside the thermal insulation member in order to cover the thermal insulation member to separate the reduced pressure space of the process chamber into a film deposition gas supplying space to which the film deposition gas is supplied and a thermal insulation space to which the cooling gas is supplied, the thermal insulation member holding structure holding the thermal insulation member separated from the process chamber to form the thermal insulation space defined between the process chamber and the thermal insulation member holding structure.