This study proposes a bent wire monopole antenna to achieve impedance matching in the frequency range of 950−1,050 MHz and a directive radiation pattern in the target direction (φ=180°, 40°<θ<50°). A machine learning technique based on a deep neural network is applied to obtain an optimal antenna design that is bent at three points to adjust the impedance and radiation pattern. The machine learning model is trained using a dataset that includes the antenna geometry and cost, evaluated on how well the antenna performance satisfies the target bandwidth and radiation pattern. After verifying that the machine learning model is trained using the figure of merit, the machine learning model is validated by comparing the cost estimated by the model with that estimated by a commercial electromagnetic simulator. Next, we obtain the optimal antenna design from the result of a grid search and fabricate it to verify its performance. The results show that the manufactured antenna has a matching bandwidth from 983.5 to 1,037.5 MHz and a radiation gain of approximately 4 dBi in the target direction. These results are in good agreement with the simulated performance of the antenna. Thus, we conclude that the antenna design obtained using the machine learning technique is valid for designing the proposed antenna.