The present disclosure relates to an external antenna for an earphone jack, and more particularly, to an external antenna for an earphone jack, which can be used while connected to an earphone jack and can be used as a touch pen. The external antenna comprises: a touch pen chalk slot (630) formed in the rear end of a plug (600); and a touch pen chalk (650) inserted and fixed in the touch pen chalk slot (630), wherein the external antenna can be used as a touch pen for controlling the touch screen of a portable terminal.
