The invention concerns an image-capturing apparatus and an imager. The image-capturing apparatus includes the imager in which a plurality of circuit cells are two-dimensionally aligned, and an electronic charge, photo-electronically converted from a received light and stored in each circuit cell, can be discharged from an arbitral circuit cell. The imager includes first group circuit cells to generate electronic charges corresponding to the pixels of the image including a subject, and second group circuit cells to generate electronic charges corresponding to an amount of light coming from the subject, the electronic charges further being converted to a detected value. In the imager, at least one of two operations of halting a generating-action of the electronic charges in the first group circuit cells and discharging the electronic charges from the first group circuit cells is performed, when the detected value exceeds a threshold value.