An inductively coupled module includes a wireless IC chip and a feeder circuit substrate which is connected to the wireless IC chip and which includes a feeder circuit including an inductance element and a capacitance element. The feeder circuit substrate is made of a biodegradable plastic so as to prevent a negative impact of the module on the environment and the human body. The inductively coupled module is adhered on a radiation plate and is used as a wireless IC device of an RFID system.