An IC module (secure element with an IC card function) mounted on a portable device executes a process relating to a service, via contactless communication with a service terminal located at a certain place. At least one of the IC module and the portable device judges whether a change, made in state data related to the service and made by the process with a user's check eliminated, satisfies a condition set as requiring an attraction of a user's attention. According to the result of the judgment, a user interface function of the portable device notifies a user.