There is provided a wideband patch antenna and an antenna array. The antenna includes a dielectric substrate of a rectangle shape, a radiation patch formed on a top surface of the dielectric substrate, a coupling patch formed on the top surface of the dielectric substrate and extending from a side of the dielectric substrate to a position from the radiation patch by a distance, a metal support arranged on the lower surface of the dielectric substrate and extending from the edge of the lower surface of the dielectric substrate downward to the ground, a layer of air having a predetermined thickness being formed between the lower surface of the dielectric substrate and the ground. According to the embodiments, it is possible to improve the directivity of the wideband microstrip antenna while maintaining its small size.