An antenna having a band rejection filter. The antenna includes: a radiator formed of a single plate, a grounding part formed of a single plate, a dielectric substrate including a surface on which the radiator is attached and another surface on which the grounding part is attached, and the band rejection filter connected to an end of the radiator. The band rejection filter includes a first capacitor connected to a signal line in parallel, a resonator including an end connected to the first capacitor in parallel and another end grounded, and a second capacitor including an end connected to the first capacitor in series and another end connected to the radiator in series. The resonator includes an inductor and a third capacitor connected to the inductor in series. As a result, the antenna may remove a frequency lower than an ultra wide band pass.