A reader/writer apparatus to communicate with an external radio communication apparatus in accordance with instructions from a controller apparatus is provided. The reader/writer apparatus includes a storage unit including one or more key storing segments to store access keys that enable communication with the radio communication apparatus; an access key searching unit configured to search for an access key stored in one of the key storing segments on the basis of key-associated information that is received from the controller apparatus and that can uniquely specify the access key; and a communication unit configured to receive instructions from the controller apparatus, generate a command corresponding to the instructions, and transmit the command to the radio communication apparatus by using the access key obtained by the access key searching unit.