An ultrawideband perfect absorber (UPA) is designed via a four-layer dielectric/refractory metal structure, which can produce near-unity absorption in the midinfrared region. The maximal absorption is up to 99.6%. Moreover, the absorber can maintain excellent absorption in a wide angle range, which indicates the angle-insensitive absorption and holds potential applications in complex electromagnetic situations. The ultrawideband spectral absorption mainly results from the intrinsic broadband plasmonic resonances by the refractory metals and the combination of the different plasmonic resonances by the resonators, and the cavity resonances by the layered nanostructures. Furthermore, due to the high melting point of titanium and chromium materials, the UPA is with highly thermal stability. The proposed absorber platform is therefore with both advantageous on the absorption properties and material features, which could pave ways for a wide application prospect in solar harvesting, infrared detection, and others.