A cradle apparatus and a portable device are interconnected employing reflected wave transmission without interfering with an adjacent wireless system or impairing ease of use of the portable device. The cradle is provided with a function of a reflected wave reader and a digital camera is provided with a function of a reflector, whereby communication between the cradle and the digital camera is performed in a non-contact manner. The digital camera modulates a reflected wave of an unmodulated carrier transmitted from the cradle by varying the antenna load impedance in accordance with picked up image data, thereby performing reflected wave transmission. Communication is possible even while the portable device is somewhat apart from the cradle, and the ease of use of the portable device is not impaired even while communication is being performed.