An antenna coupler, which connects an antenna that is drawn in/out on a portable electronic device and has a hollow pipe type lower end, includes a bushing fixed to an interior of a case of the portable electronic device, a rotary support portion sliding in the bushing to be drawn into the interior of the case when the antenna is drawn in and having an upper end portion that is drawn out to outside of the case, a coupling member having an upper end that is inserted into and coupled to an interior of a lower end of the antenna, and a rotary member having an upper side that is screw-engaged with the coupled member and a lower side rotatably coupling to the upper end portion of the rotary support portion.