Multilayer solar selective absorber coatings based on three chromium aluminium nitride (CrAlN) layers with different stoichiometries and Al2O3 were deposited on 316L steel and Inconel 625 (two of the most common metallic components used in concentrated solar collectors) by means of magnetron sputtering. Combining high-power impulse magnetron sputtering (HiPIMS) with radiofrequency (RF) sources with a pulsed direct current (DC) bias on the substrates a solar selective multi-layered stack is obtained with good absorptance (α≈95%) and low emissivity (ε≈18%) values [1]. The solar performance has been evaluated after annealing in a muffle at different temperatures (600, 700 and 800 ºC) to check the thermal stability and oxidation resistance. The decrease of the absorptance values begins at 700 ºC (93%) while emissivity reaches the lowest values (about 12-13%), independently of the type of substrates. Then, two set of coatings deposited on Inconel and stainless steel have been mounted in a new test bench for a solar furnace (SF40 [2] from CIEMAT-PSA) to check their behaviour in real solar conditions. The solar fluxes were controlled to limit the maximum working temperature at 650 ºC and their optical performance was compared with commercial paint Pyromark© deposited on similar substrates during 50 h. Additionally, aging behaviour was evaluated by cycling the samples 15 times up to 650 ºC. The optical properties have been measured using portable equipment typically used in the industry as well as reference spectrophotometers in laboratories. The paper will discuss comparatively the aging behaviour of the multilayer solar selective absorbers upon the different treatment conditions.