A camera comprises: a photographing unit converting an image formed by a shooting lens into an electric signal; a subject brightness obtaining unit; an exposure computing unit computing a shutter speed and an aperture value; a shutter controlling a time period in which the photographing unit accumulates the electric signal; and an aperture control unit controlling an aperture value of an aperture unit that limits a quantity of light incident from the shooting lens, wherein the exposure computing unit calculates a deviation between a previous exposure amount and a proper exposure amount on the basis of brightness information relating to a previous exposure and output by the subject brightness obtaining unit, the aperture value of the aperture unit, and the shutter speed of the shutter, and computes an aperture value of the aperture unit for a subsequent exposure on the basis of the deviation.