An apparatus and method for authenticating a telematics terminal are disclosed to receive a first telematics service based on inputted user authentication information and then easily receive a second telematics service based on the inputted user authentication information. A fluid such as compressed air is passed over a desiccant in a drying tower to adsorb moisture from the compressed air. The antennas in the antenna array are continuously selected as a transmitting antenna by switching, and continuously emit transmission signals.