A speaker device installed in an earpiece, for improving an antenna property in a wireless portable terminal is provided. The speaker device includes a housing, a magnet is installed on the housing, a diaphragm located a predetermined distance away over the magnet and includes a coil situated at a position corresponding to the magnet, and a cover covers the diaphragm and is in engagement with the housing, thereby forming a module. At least one inductor is provided at a feeding portion of the coil formed or installed on the diaphragm, thereby preventing the speaker device from resonating at a radio frequency (RF).