An antenna device of an electronic apparatus, according to embodiments of the present invention, includes radiation patterns comprising: at least one open boundary; and a plurality of radiation sections having the open boundary placed and arranged therebetween, wherein the radiation pattern forms a resonant frequency in a first frequency band (hereinafter, referred to as “a first resonance frequency”) and at least one among the radiation sections can form a resonant frequency in a second frequency band (hereinafter, referred to as “a second resonant frequency band”) higher than the first resonant frequency. The antenna device of the electronic apparatus, according to the present invention, can be implemented through other various embodiments.