To make a positional-information transmitting device microminiature to be capable of being carried by children or old people without any burden.

In the positional-information transmitting device, a tracking device chip 2 in which a GPS receiver, a radio communication device and a control circuit are formed as one chip, an antenna 3 and a battery 4 are built in a badge 1 or a name card. The radio communication device is usually in a pause state, and it is set to a standby state only for a short time about several times per hour. When a family notices that its child is missing, it makes contact with a center. The center calls the radio communication device, and it issues a command so as to notify positional information data. The transmitting device receiving the command operates the GPS receiver so as to acquire the positional information data. The data is notified to the center by using the radio communication device. By repeating this procedure, the center can track the position of the child.