An accessory that can be attached to a camera body, the camera body including a first camera-side clock terminal that outputs a first clock signal, a first camera-side data terminal that outputs a first data signal, and a third camera-side data terminal to which a third data signal is input, the accessory includes: an eighth terminal that is brought into contact with the first camera-side clock terminal; a seventh terminal that is brought into contact with the first camera-side data terminal; and a ninth terminal that is brought into contact with the third camera-side data terminal, wherein the eighth terminal is positioned between the seventh terminal and the ninth terminal.