PURPOSE: To enable cooling effect of a substrate when performing etching to be improved and prevent pattern deviation by providing a flexible material between the X-rays mask substrate and a cooling stage.

CONSTITUTION: An X-rays mask consisting of 1, 2, and 3 is fixed to a sample stage 4 within a vacuum tank, inside of the vacuum tank is set to an etching gas environment, a cooling stage 5 where a flexible material 6 is provided on an upper surface is cooled to a specified temperature by liquid nitrogen, etc., a cooling stage 5 is lifted, and then it is adhered onto the substrate 1. A pattern 2 is formed by RIE. In this case, temperature increase of the substrate 1 due to plasma is prevented due to heat conduction of cooling effect from the cooling stage 5, thus preventing generation of pattern deviation. Also, the substrate 1 can be protected by the flexible material 6. Also, after the pattern 2 is formed, the flexible material 6 can be eliminated by a solvent easily since the flexible material 6 is polymer, etc.