PURPOSE: To decrease the number of the photomask to be used at the time of transferring prescribed patterns to one sheet and to reduce the cost thereof by providing one set of transparent electrodes which are formed on the surface of a light transmissive substrate and are parallel with the surface and a liquid crystal between the electrodes.

CONSTITUTION: This photomask has the light transmissive substrate 11, the matrix- shaped transparent electrodes 12, 13 which are formed on the substrate 11 in parallel therewith and apply voltages between the electrodes only in the parts to be formed as light shielding parts, and the liquid crystal 14 which exists between the electrodes 12 and 13 and becomes opaque when impressed with the voltage. The upper electrodes 13 and the lower electrodes 12 are so formed as to intersect orthogonally with each other at 1μm width and 0.5μm intervals. The liquid crystal 14 in the parts interposed in the upper and lower electrodes makes a reversible structural change and does not allow the transmission of light any longer if one side of the electrodes positioned above and below the parts desired to be shielded of light is connected to GND and the other side is maintained at 1.0 to 5.0V potential. The light shielding parts of arbitrary shapes are generated on the photomask in this way and the generation of all the patterns with one sheet of the photomask is possible. The cost is thus reduced.