1. An imaging device, comprising: an imaging component configured to continuously capture a subject and produce a plurality of sets of image data; a controller configured to set a priority for executing image processing on at least one of the plurality of sets of image data; and an image processor configured to execute image processing on each of the plurality of sets of image data on the basis of the priority; wherein the controller is configured to set the priority of the image data such that the priority of new image data is higher than the priority of old image data among the plurality of sets of image data produced by the imaging component which are not being processed or previously processed by the image processor; the controller is configured to set the priority before and while the image processor executes the image processing of image data which has a first highest priority, the first highest priority set after starting the previous image processing of the image processor; the image processor is configured to execute image processing on the new image data which has a second highest priority after the image processor has executed the image processing of image data which has the first highest priority; and the controller is configured to change a priority order of the image data during image processing being performed by the image processor.