The object of the invention is to provide a noncontact IC card
reader/writer integrated with an antenna that does not require the
limitation of an installation location and the adjustment of a resonance
frequency of the antenna, is convenient in installation, is provided with
a stable characteristic, is small-sized and low-priced. To achieve the
object, the invention is provided with a loop antenna that supplies
electric power and send data to a noncontact IC card by electromagnetic
induction and acquires receive data from the noncontact IC card by load
fluctuation, a magnetic body arranged closely at the back of the loop
antenna, a first metallic plate arranged on the back side of the magnetic
body and a second metallic plate arranged on the back side of the first
metallic plate and larger than the first metallic plate in size.