An image capturing device includes a first controller operable to control image capturing; an operation section including a switch; a detector operable to detect a change to an image capturing mode and to send a signal representing the change; a second controller operable to monitor and process the sent signal, the second controller having a power consumption less than that of the first controller; and a power supply operable to supply power to the first controller, the second controller, and a functional section of the device. When the second controller receives the signal sent from the detecting section in a power saving state in which power is supplied from the power supply to the second controller, the power saving state is changed to a power supplying state capable of image capturing by supplying power from the power supply to portions of the device including the first controller.