An image sensor driving unit, comprising a first controller, a second controller and a third controller, is provided. The image sensor driving unit drives an image sensor to carry out the capture of an image. The capture is carried out by ordering pixels to generate signal charges and the charge-transfer channel to transfer the signal charges. The first controller orders the image sensor to carry out a rapid discharge operation before the charge-transfer channel transfers the signal charges. The second controller controls the first controller to order the image sensor to carry out the rapid discharge operation when light is made incident for capture after the first capture with the image sensor operating in continuous photographing mode. The third controller decreases the discharge number for capture after the first capture.