Information search system includes terminal having speech communication function and packet communication function and center for selectively performing speech communication and packet communication with the terminal. Center includes speech control section, speech recognition section, information search section, speech conversion section, and packet control section. Speech control section performs speech communication with the terminal packet communication. Speech recognition section recognizes speech signal received by speech control section and sent from the terminal. Information search section searches for information on the basis of speech information recognized by speech recognition section. Speech conversion section converts speech information of the information searched out by information search section into speech signal and outputs it to speech control section. Speech signal from speech conversion section is transmitted to the terminal by speech control section. Packet control section transmits image/character information of the information searched by information search section to the terminal by packet communication.