The present invention relates to the use of alkali metal promoted aluminosilicate zeolite catalyst for the direct gas-phase conversion of glycerol to glycidol, as well as to a process for the production of glycidol from glycerol in a fixed-bed continuous flow reactor in the presence of such a heterogeneous catalyst. The method comprises conversion of glycerol to glycidol in the range of temperature 250-450 °C, glycerol concentration 1-60 wt%, total gas hourly space velocity 100-2500 h-1, weight of catalyst 0.5-5.0 g.