To facilitate guidance with a map and update the map by receiving a constant broadcast signal from a transmitting station different in region, and extracting and storing map information of each region in the received broadcast signal.

A specified frequency signal from a transmitting station different in region is received with an antenna 11, and treated and detected with a high frequency part 12 controlled by a receiving control part 24, and an I component and a Q component are obtained. Both of the components are subjected to digital conversion by an A/D converter 13, and to fast Fourier transform by an OFDM(orthogonal frequency division multiplex) demodulation part 14. The transformed serial data are subjected to Viterbi decoding by a Viterbi decoder 15, and each sound program and data program in a main service channel are obtained. A program of road map data in the data program is extracted by a data detecting part 22 for navigation, then supplied to a control part 34 for navigation, and stored in a storage device 35 connected with the control part 34. Thereby map information of each region can be effectively obtained.