Provided is a bent monopole antenna. The bent monopole antenna includes a printed circuit board, an RF module, a feed line, and a main radiation pattern part and a sub-radiation pattern part. The RF module is installed the printed circuit board to generate an electrical signal. The feed line is connected to the RF module to deliver the electrical signal. The main radiation pattern part and the sub-radiation pattern part serve as a radiation pattern part connected to the feed line to generate an electromagnetic field (electromagnetic waves) using electrical signals applied thereto. The main radiation pattern part has a spiral (helical) pattern passing through the printed circuit board through a via.