A film-forming apparatus, comprising: a rotary shaft; a rotary stage connected to the rotary shaft and configured to hold a plurality of wafers in a plurality of placement regions disposed in a circumferential direction with respect to a central axis line of the rotary shaft, the rotary stage having a first surface on which the plurality of wafers is held and a second surface opposite the first surface; a susceptor configured to accommodate the rotary stage in an internal space of the susceptor, the susceptor having an upper inner surface facing the first surface of the rotary stage and a lower inner surface facing the second surface of the rotary stage; a gas supply mechanism configured to generate a flow of a process gas along a direction orthogonal to the central axis line from the outside of the rotary stage in the internal space; a container configured to accommodate the susceptor; and a first heat insulating material installed between the container and the susceptor so as to cover the susceptor, the susceptor is further configured to heat the rotary stage by radiant heat of the susceptor; characterized in that a second heat insulating material is installed in a heat insulating region existing in the internal space and is configured to inhibit the radiant heat of the susceptor from being radiated to the heat insulating region; and the heat insulating region is located between the second surface of the rotary stage and the lower inner surface of the susceptor and is located more outward with respect to the central axis line than positions in the plurality of placement regions nearest to the central axis line and more inward with respect to the central axis line than positions in the plurality of placement regions farthest from the central axis line. a rotary shaft; a rotary stage connected to the rotary shaft and configured to hold a plurality of wafers in a plurality of placement regions disposed in a circumferential direction with respect to a central axis line of the rotary shaft, the rotary stage having a first surface on which the plurality of wafers is held and a second surface opposite the first surface; a susceptor configured to accommodate the rotary stage in an internal space of the susceptor, the susceptor having an upper inner surface facing the first surface of the rotary stage and a lower inner surface facing the second surface of the rotary stage; a gas supply mechanism configured to generate a flow of a process gas along a direction orthogonal to the central axis line from the outside of the rotary stage in the internal space; a container configured to accommodate the susceptor; and a first heat insulating material installed between the container and the susceptor so as to cover the susceptor, the susceptor is further configured to heat the rotary stage by radiant heat of the susceptor; characterized in that a second heat insulating material is installed in a heat insulating region existing in the internal space and is configured to inhibit the radiant heat of the susceptor from being radiated to the heat insulating region; and the heat insulating region is located between the second surface of the rotary stage and the lower inner surface of the susceptor and is located more outward with respect to the central axis line than positions in the plurality of placement regions nearest to the central axis line and more inward with respect to the central axis line than positions in the plurality of placement regions farthest from the central axis line.