An antenna module includes a dielectric substrate, a radiation electrode formed on the front face of the dielectric substrate, an RFIC and a ground electrode formed on the rear face of the dielectric substrate, a ground line arranged in the dielectric substrate, and a power supply line including a power supply line portion arranged in parallel to a main surface of the dielectric substrate. The ground electrode is arranged between the power supply line portion and the RFIC. The ground line is arranged between the power supply line portion and the radiation electrode. The ground electrode includes the radiation electrode and part of the power supply line portion in a plan view. The ground line includes part of the power supply line portion in the plan view. The area in which the ground line is formed is smaller than the area in which ground electrode is formed.