1. A digital camera comprising: a photographing component for photographing a subject; a setting component for setting whether a generation of an intermediate image is to be carried out, and for setting a resolution of an original image, so that if the generation of the intermediate image is to be carried out, the setting component sets a resolution of the intermediate image based on a set resolution of the original image; an intermediate image generating component for generating, when the intermediate image generation is set by the setting component, the intermediate image for verifying a state of focus, having the resolution which is between a resolution of the original image and a resolution of a thumbnail image; and a storage component for storing an original image photographed by the photographing component and, if generated, the generated intermediate image, wherein, when the set resolution of the original image is changed to a new set resolution, the setting component automatically changes the resolution of the intermediate image based on the new set resolution of the original image.