PURPOSE: To prevent destruction of a pattern and attraction of dust due to electrostatic charging and to form the pattern with high precision by injecting metal ions into the surface of a transparent quartz plate for constituting a quartz mask and reducing its surface resistivity.

CONSTITUTION: The transparent quartz plate small in thermal expansion coefficient and in change due to the lapse of time, but high in resistivity and liable to be charged is used for the quartz mask, and the ions of a metal, such as Cr, are injected into the whole surface of the plate in such a range as to slightly impair the transmittance of ultraviolet rays, thus permitting the surface resistivity to be remarkably lowered and charge to be eliminated, a formed transparent conductive film to be hardly removed by the presence of the metal ions inside the substrate, and the obtained mask to be repeatedly used, and a pattern to be formed with high precision without any destruction and attraction of dust due to charging.