The present invention relates to an ultra wideband internal antenna, which is provided in a mobile communication terminal to cut off frequencies in a certain frequency band while processing ultra wideband signals. The ultra wideband internal antenna includes a first radiation part, a second radiation part, a feeding part and a ground part. The first radiation part is made of a metal plate on a top surface of a dielectric substrate and is provided with at least one cut part, formed by cutting out a lower corner portion thereof, and an internal slot. The second radiation part is formed in the slot of the first radiation part while being connected to the first radiation part, the second radiation part being conductive. In this case, the first and second radiation parts form an ultra wide band due to electromagnetic coupling therebetween using individual currents flowing into the first and second radiation parts.