Fabricating a high contrast and highly accurate gold absorber pattern has been considered for an x‐ray mask. In this method, the polyimide patterns etched by O2‐reactive ion etching are used for the plating mask. In electron beam pattern generation, few electrons are backscattered from the polyimide film. Those from the electroplating base are trapped in the polyimide film, which improves the electron beam resolution. In O2‐reactive ion etching of the polyimide film, an accurate pattern without etch residue is obtained by using the carbon target. The titanium adhesion layer for the plating base is etched off by CBrF3‐reactive ion etching without undercut. A gold pattern with 0.5 μm in width and 1.0 μm in thickness can be obtained within 0.1 μm accuracy by a combination of these technologies.