An antenna module has a substrate, a radiating element disposed in or on the substrate, a power feeding line, and a dielectric body. The substrate has a rectangular shape including first and second sides adjacent to each other. The power feeding line extends in a normal direction of the substrate and transfers radio frequency signals supplied from an RFIC to the radiating element. The dielectric body is disposed on a side surface of the substrate. The power feeding line is coupled to the radiating element at a position offset from the center of the radiating element in a first direction toward the first side. The dielectric body is disposed so as to cover the side surface of the substrate including the first side. The dielectric constant of the dielectric body is higher than the dielectric constant of the substrate.