To supply stable power to an IC card which does not have a battery and to maintain stable communication with an interrogator by using a line G (Goubau line) whose one end is terminated in terms of high frequency with a load.

The signal of a carrier signal source 9 which is PLL-controlled and outputs the signal of a micro wave is modulated, amplitude-modulated, for example, with a transmission signal inputted from a transmission signal input terminal 14 through an interface circuit 11 and a band is restricted. The signal is excited by an electromagnetic horn 7 installed in the exciting part of a line G through a directional coupler 28 and a circulator 12. It is transmitted on the surface of the line G and is consumed in a load circuit 16 through an electromagnetic horn 8 installed in the terminating part of the line G. The intensity of an electromagnetic field within a prescribed distance is set to ≥a setting value from the part of the G line 6 of the system. When the IC card types such as a first IC card or a second IC card are arranged in an electromagnetic field area, prescribed power is obtained from the line G.