An imaging device includes an imaging element which obtains an image, and an imaging sensor processing unit which resets an exposure of the imaging element by a feedback control based on an image data obtained by the imaging element. The imaging sensor processing unit continuously executes, by pipeline processing, the following processing of setting an exposure time of the imaging element in a first frame just after start-up of the imaging device, making the imaging element accumulate light with an exposure time set at a former frame in a second frame, and outputting the image data by applying a gain set by the second frame in a third frame.