A digital processing device capable of receiving an additional service is disclosed. In one aspect, a digital processing device includes i) an input unit, inputting a signal, ii) a subscriber identity unit, storing an identity code of a communication operator and generating a communication network access request message, iii) an additional service identity unit, storing an identity code of an additional service operator and generating an additional service request message and v) a control unit, generating a control signal allowing one of the subscriber identity unit and the additional service identity unit to be selectively driven. In accordance with at least one inventive embodiment, a user of the digital processing device can receive an additional service without his or her subscription to a specific communication operator and use various additional services in addition to the additional services provided by the subscribed communication operator.