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 second camera-side clock terminal to which a second clock signal is input, and a first camera-side power supply terminal that outputs first power, the accessory includes: an eighth terminal that is brought into contact with the first camera-side clock terminal; a tenth terminal that is brought into contact with the second camera-side clock terminal; and a second terminal that is brought into contact with the first camera-side power supply terminal, wherein: a distance between the tenth terminal and the second terminal is longer than a distance between the eighth terminal and the second terminal.