When a user of a mobile communication terminal makes a request for a position-measuring of a current location, at step S101, a position-measuring method determining section checks a position-measuring method specified. When the method specified is a "cell ID position-measuring", and it is performed, when the method specified is a "base station radio waves position-measuring"; a base station radio waves position-measuring is performed, when the method specified is a "GPS position-measuring" or a "not specified", at step S102, a judgment of whether an area in which the mobile communication terminal exist is an area suitable for data communication is made. When the judgment is negative, an autonomous GPS position-measuring is performed. When the judgment is affirmative, an assisted GPS position-measuring is performed. In this case, when the assisted GPS position-measuring has failed, in process to deal with failure of assisted GPS position-measuring at step S108, in a case of predetermined conditions, further the autonomous GPS position-measuring or a supplementary cell ID position-measuring is performed.