An imaging device comprises an imaging section for outputting image data every set time, in association with bulb exposure commencement; an adding processing section for generating an added image by adding images that were output after commencement of the bulb exposure; an image display section for displaying each generated added image; and a display illumination section for illuminating a display screen of the image display section, and if an update period for image display on the image display section is a predetermined time or longer, illuminates the display screen of the image display section for a time that is shorter than the update period, in response to update of image display on the image display section, while if the update period is less than the predetermined time, continuously carries out illumination.