In this work, we report on the spectroscopic characterization at both room and elevated temperatures of a selective metamaterial solar absorber made of a 2D titanium grating deposited on an MgF2 spacer and an opaque tungsten film, as illustrated in Fig. 1a. Tungsten is chosen as the substrate material due to its excellent high-temperature stability and high absorption in the visible and NIR regime. Titanium rather than tungsten in Ref. [19] is selected for the grating materials because of its easiness to pattern in deposition and lift-off processes. MgF2 is used for the dielectric spacer considering its better CTE (i.e., coefficient of thermal expansion) match with tungsten and titanium than other dielectrics like SiO2 to minimize the possibility of thermal cracking at high temperatures. The near-normal specular and hemispherical reflectance is measured over a broad spectral range from UV to the mid-IR regime, demonstrating its spectral selectivity. The electromagnetic field distribution obtained from finite-difference time-domain (FDTD) simulation is plotted at absorption peaks to explain underlying mechanism. The effects of oblique incidence, polarization state, as well as temperature up to 350 °C are further experimentally investigated. Finally, the solar-to-heat conversion efficiency for the metamaterial solar absorber is predicted to show its excellent performance especially at high absorber temperatures