Provided are: an imaging device with which it is easy to set area for which exposure is controlled; a control method for the imaging device, and a control program for the imaging device. The imaging device comprises: an imaging unit which outputs an image signal obtained through capture by imaging elements which capture an object through an imaging optical system; a display which displays a captured image according to the image signal; and a control unit which determines the position of a boundary line which divides the captured image into a plurality of areas, on the basis of analysis resultsof the captured image, and if there has been a change in the captured image, adjusts the position of the determined boundary line on the basis of the change in the captured image, or controls the exposure in at least one of a plurality of areas divided by the adjusted boundary line on the basis of the brightness of the captured image after the change.