An information device makes a payment with a payment terminal through a contactless communication, using amount data of an electronic purse function of a mobile device. The mobile device with the electronic purse function permits the information device to be used for performing payment processing with the payment terminal, using amount data of the electronic purse function of the mobile device. A wearable information device includes an image taking unit configured to take an image of an object in the direction of line of vision of a user, and notifies the information device of the presence or absence of the information device in a taken image. The information device makes a payment with the payment terminal through a contactless communication based on the notification from the wearable information device of the presence or absence of the information device.