A wireless card reader system includes: a card reader terminal that is battery-driven and obtains card data for verification; a high-order host apparatus that verifies the card data, changes an operating state of a target device when a verification result is successful, and sends the verification result; and an interface apparatus that relays communication between the card reader terminal and the high-order host apparatus. The card reader terminal is operable in a normal mode or in a sleep mode. The card reader terminal switches to the sleep mode after sending the card data in the normal mode. The card reader terminal temporarily returns from the sleep mode to the normal mode to perform polling to the interface apparatus, and obtains the verification result. The polling is performed less frequently in a period before a state change than in a period after the state change.