The present invention provides a mounting mat (30) for mounting a pollution control monolith (20) in a pollution control device (10). The mounting mat has a bulk density of 0.12 to 0.3 g/cm3 and comprises (i) a layer of chopped magnesium aluminium silicate glass fibers and (ii) a layer of ceramic fibers obtainable from a sol-gel process. Preferably, the layer of chopped magnesium aluminium silicate glass fibers and the layer of ceramic fibers define opposite major surfaces of the mat. The present invention further provides a pollution control device (10), comprising a pollution control monolith (20) arranged in a metallic casing (11) with the mounting mat (30) disposed between the metallic casing (11) and pollution control monolith (20).