An antenna unit and an antenna array. The antenna unit includes M layers of cross metal patches, M layers of dielectric substrates, and a metal ground layer, where M is an integer greater than 1. In addition, an ith-layer dielectric substrate is disposed between an ith-layer cross metal patch and an (i+1)th-layer cross metal patch. The ith-layer cross metal patch, the ith-layer dielectric substrate, and the (i+1)th-layer cross metal patch are sequentially stacked, and i is an integer ranging from 1 to M−1. An Mth-layer cross metal patch, an Mth-layer dielectric substrate, and the metal ground layer are sequentially stacked. The antenna unit and the antenna array formed by units may have a good polarization feature, a relatively wide operating bandwidth, and a relatively good phase shift feature.