The pre-irradiation annealing was studied in the temperature range of 100 … 350 °C for silicate glass at different annealing times. The annealing raising the tracks density. The optimum annealing temperature was 250 °C. The annealing time was found to be hardly effected at the first hundred hours. The preannealing was found to be the hardness of the silicate glass so that the bulk etching rate decreases. The activation energy for bulk etching was found to be (0.3135 eV), the annealing did not change its value.