An imaging apparatus that images an image with a solid-state imaging device includes an area defining section that defines an unnecessary image detection area, which may contain an unnecessary image, at a position along an outer edge of an imaged image obtained by the solid-state imaging device, a focus evaluation value calculating section that calculates a focus evaluation value, which indicates the focal degree, based on an image signal of the imaged image obtained through a gradually moved focus lens, an unnecessary image detection processing section that determines that the imaged image contains the unnecessary image if the focus evaluation value calculated based on an image signal in the unnecessary image detection area has a peak while the focus lens is moving, and a warning processing section that performs processing for warning a photographer of the fact that the unnecessary image is contained if it is determined.