PURPOSE: To reduce the fatigue of eyes, trouble, etc., of a person in charge of retrieval by discriminating picture data and sound data, transmitted from a data center, by a terminal unit according to data discrimination codes and then by outputting them to a picture display part and sound generation part.

CONSTITUTION: In response to an information service request from terminal unit 50, data center 10 reads picture data and sound data out of their files and then transmits them to terminal unit 50 together with additional data discrimination codes. Under the control of control part 55, terminal unit 50 discriminates and separate picture data and sound data according to the above-mentioned data discrimination codes to display picture data at picture display part 51 while outputting sound data from sound generation part 53 in the form of a sound. In tis case, a specific number is dialed from telephone set 52 at the terminal side, for example, to connect terminal unit 50 to data center 10 via switchboard 30 and then information required for retrieval, etc., is inputted from keyboard 54.