An intermediate accessory enables a camera and an exchange lens to communicate with each other through an information processor configured to provide predetermined processing for information received from one of the camera and the exchange lens, and to transmit information that has undergone the predetermined processing, to the other of the camera and the exchange lens, while the camera and the exchange lens are being attached. The intermediate accessory obtains lens identification information from the exchange lens, which is used to identify the exchange lens. The intermediate accessory enables a camera and an exchange lens to communicate with each other without intervening the information processor and transfers to an operation restricting mode used to restrict at least part of an operation the intermediate accessory, when the lens identification information indicates a specific exchange lens that does not require the predetermined processing.