An image pickup device which makes it possible to expand the dynamic range of photometry. The image pickup device comprises a pixel array, a pixel reader, a row selector, a column selector, a gain circuit, a gain selector. The pixel array comprises a plurality of pixels including photoelectric conversion elements and arranged in the horizontal direction and in the vertical direction. The pixel reader reads out selected pixel signals from the pixel array. The gain circuit is capable of having at least two gains set therein, and amplifies and outputs the pixel signals read out from the pixel array by the pixel reader. The gain selector sets different gains in the gain circuit such that pixel signals amplified by the different gains can be obtained for one-time read-out from the pixel array by the pixel reader.