In a multiple loop antenna comprising a combination of a plurality of loop antennas, at least one factor among the diameter of each loop antenna, the number of turns thereof, the direction thereof, the effective permeability thereof, the relative values of electric currents of loop antennas and the phase difference of electric currents is controlled in such a way that the magnetic field intensity within the range extending from the multiple loop antenna to the distance of transmission wavelength of the multiple loop antenna decreases in inverse proportion to the n-th power (n>3) of the distance from the multiple loop antenna. This makes it possible to obtain a multiple loop antenna that has a high-intensity magnetic field within the predetermined communication zone but can steeply decrease the magnetic field intensity according to an increase in distance from the antenna and surely control the magnetic field intensity to be not greater than a stated value on the outside of the communication zone.