A conversion lens attachment structure includes a first magnetic body provided on a conversion lens device that includes a conversion lens, and a second magnetic body provided on a device main body that includes a master lens. The conversion lens device is attached to the device main body due to a first surface of the first magnetic body and a second surface of the second magnetic body being pulled toward each other, and the second magnetic body is provided such that a normal line of the second surface is not parallel to an optical axis of the master lens.