To improve a temporal resolution.An image-capturing device includes a pixel array unit and a control unit. The pixel array unit includes a plurality of pixels classified into two or more groups, wherein pixels which belong to a same group are driven at a same timing. The control unit controls driving of the pixel array unit so that a number of groups in a period of time of read-out of electrical charge is a same number in any given timing in image-capturing operation, and that a number of groups in a period of time of exposure and accumulation of electrical charge is a same number in any given timing in the image-capturing operation.