1. A reader device reading information from an information storage medium, wherein the information storage medium includes an IC chip executing a command transmitted from the reader device; and the reader device comprises: a command communicator transmitting a plurality of commands to the information storage medium and receiving a plurality of response signals from the information storage medium obtained as a result thereof; a storage storing feature points of the IC chip; a genuine/counterfeit judger extracting the feature points from at least one of the response signals from the information storage medium and judging whether the IC chip is a genuine or counterfeit one on the basis of the extracted feature points; and a communication controller causing the command communicator to transmit a first command and, after receiving a first response signal from the information storage medium obtained as a result thereof, causing the command communicator to successively transmit a second command that is the same as the first command and that has a different communication specification.