A light device includes a light source that irradiates light to the outside; a positional information transmission part that transmits positional information of the light device to a wireless terminal; a terminal information reception part that receives identification information of the wireless terminal and the positional information from the wireless terminal that has received the positional information; a terminal information transmission part that transmits the identification information and the positional information to a management server that manages a position of the wireless terminal; and a voltage conversion part that converts a voltage of power supplied from an external power source and supplies the power to the positional information transmission part, the terminal information reception part and the terminal information transmission part.