Abstract: A new type of metamaterial absorber with ultra wideband absorbing performance which is based on metal film of tantalum nitride and porous foam is proposed. The frequency band of which absorbance is more than 80% range from 15.5 GHz to 47.2 GHz (the maximum absorbility achieves 99.89% at 18.3 GHz). The relative bandwidth is approximate of 101% and the operating frequency fully covers the K-band and Ka-band and partly U-band. For the oblique incidence electromagnetic wave of TE mode and TM mode, the absorber exhibits the absorbing property of wide angle. Due to the metal pattern in the metamaterial absorbing cell composed of five concentric rings with omnidirectional rotation symmetry, the absorber possesses excellent polarization independent characteristics. The presented absorber has the advantages of simple structure, easy fabrication, thus it has important application value in the fields of electromagnetic stealth and electromagnetic compatibility.