In order to meet the demand for broadband absorbers in the infrared transparent window of the atmosphere, we designed an ultrabroadband metamaterial absorber (MA), which is composed of a germanium-zinc sulfide-chromium-zinc sulfide (Ge-ZnS-Cr-ZnS) disk periodic array and a chromium (Cr) bottom layer. In the infrared transparent window of the atmosphere, the average absorption of the MA is as high as 99.1%, and ultrabroadband near-perfect absorption is realized. Moreover, the absorber is polarization independent and insensitive to the angle of incidence. The ultrabroadband and high-absorption metamaterial absorber has broad application prospects in solar cells, photodetectors, thermophotovoltaics, and thermal emitters.