Abstract: An antenna apparatus includes a radiation member and a substrate having a ground conductor. The radiation member has a plate-like shape, is made of a dielectric material, and includes a radiation conductor. The radiation member is joined to a surface of the substrate. The radiation conductor includes a feeding portion, at least a pair of notch portions, and a step. The feeding portion is exposed from a center at one end of the dielectric material and coupled to a feeding pad provided in the substrate. The notch portions are symmetrically formed. The step is formed by a bend between the feeding portion and one of the notch portions. The radiation conductor on a side of the feeding portion from the step is embedded in the dielectric material.