PURPOSE: To improve an exposure efficiency and to also improve mechanical strength of a mask by comparatively disposing a region indicating a relatively high reflectivity in a predetermined direction to an incident X-ray and a region indicating a low reflectivity on an incident X-ray incident surface in response to an original pattern.

CONSTITUTION: A region 12a indicating a relatively high reflectivity in a predetermined direction to an incident X-ray Ii and a region 13a indicating at least low reflectivity are comparatively disposed on an incident X-ray Ii incident surface 12 in response to an original pattern. In formation of the pattern is placed on the X-ray Ir in the predetermined direction, and a pattern responsive to the pattern is obtained on an object 14 placed in an optical path of the X-ray Ir. For example, a substance layer 13 of carbon or the like having X-ray absorptive power exhibiting low reflectivity to the X-ray Ii is disposed on the surface 12 of a molybdenum substrate 11 of a mirror-finished surface. In which king of comparison relation the regions 13a and 12a are disposed in a plane shape is determined in response to the pattern.