To provide an information processor in which a place where the information processor is installed can be accurately grasped.

A central control unit 31 in a Karaoke system 10 is connected to a charging communication network 5 via a communication control apparatus 27 and receives a telephone number of a public telephone line 6. Subsequently, the central control unit 31 collates the received telephone number with a telephone number stored on a hard disk 33 within the same Karaoke system 10. When the telephone number is not matched as a result, a new telephone number is transmitted to an information center 1. The information center 1 specifies a terminal management apparatus in charge of the area of a local number of the received telephone number, reads a telephone number of the public telephone line 6 to which the management apparatus is connected, and transmits the telephone number to the Karaoke system 10. The Karaoke system then accesses the terminal management apparatus on the basis of the received telephone number and transmits an ID number and a telephone number of the Karaoke system 10.