PURPOSE: To obtain a decorative holography diffraction grating pattern which can form a two-dimensional holography pattern at low cost by a computer and a very large holography pattern, and to provide the method for forming the pattern.

CONSTITUTION: A desired pattern is formed of a collection of many individual spots, which each have a holography diffraction grating having a grating interval, an angle, and a direction determined for the spot. Desired holography effect can be obtained by varying angles and directions, and/or diffraction grating intervals among the spots or spot groups. The spot positions can be varied as desired into positions where the desired pattern is drawn or into a two-dimensional orthogonal matrix for drawing the pattern by the variation between spots and/or spot groups like a raster scan type image.