An antenna device is provided. The antenna device includes: a first dielectric layer; a second dielectric layer disposed on the first dielectric layer; a third dielectric layer disposed between the first dielectric layer and the second dielectric layer; a feed via configured to penetrate the first dielectric layer; a first feed pattern disposed between the first dielectric layer and the third dielectric layer; a second feed pattern disposed between the second dielectric layer and the third dielectric layer and configured to overlap the first feed pattern; and a patch antenna pattern disposed on the second dielectric layer and configured to overlap the first feed pattern and the second feed pattern, wherein a dielectric constant of the third dielectric layer is less than a dielectric constant of the first dielectric layer and a dielectric constant of the second dielectric layer.