AUXILIARY ELECTRODE FOR ELECTRIC-FIELD COMMUNICATION

PROBLEM TO BE SOLVED: To improve a return path efficiency to prevent deterioration in communication quality when performing electric-field communication between a portable electric-field communication terminal and an installation type electric-field communication terminal via an electrode provided on a floor surface or a wall surface.SOLUTION: A first electric-field communication device 1 is taken around with a human body that is an electric-field transmission medium, and a second electric-field communication device 2 has a signal electrode 31 and a ground electrode 32 installed on a floor surface. An auxiliary electrode for electric-field communication has: a first auxiliary electrode 61 installed on a wall surface 9 approximate to the human body; a second auxiliary electrode 62 installed on a lower surface or an upper surface of the ground electrode 32; and a lead wire 63 connecting between the first auxiliary electrode 61 and the second auxiliary electrode 62.