The antenna module implemented using a multi-layer substrate comprises: a radiator which is arranged in the inner region or the upper region of the multi-layer substrate, and which has at least one conductive layer to radiate a wireless signal; a feeding structure connected to the radiator through a signal via arranged in the lower region of the radiator; a lower ground layer which is arranged in the lower region of the conductive layer constituting the radiator and which operates as a ground for the radiator; and a multi-layer ground structure which is connected to the lower ground layer, and which has end portion positions that differ for each layer of the multi-layer substrate so as to be spaced different distances apart from the radiator for each layer of the multi-layer substrate.