A film forming apparatus, including a base having a first chamber, an upper cover for at least covering an opening of the first chamber, and a first seal ring between the upper cover and the base, wherein the upper cover has an inclined slope, an orthographic projection of the slope in a plane where a bottom surface of the base is located overlaps with a region surrounded by an orthographic projection of the first seal ring in the plane where the bottom surface of the base is located, the orthographic projection of the slope is located is outside an orthogonal projection of the first chamber, and a portion of the slope close to the first chamber is away from the bottom surface of the base with respect to a portion of the slope away from the first chamber.