PURPOSE: To make it possible to describe chip patterns with little positonal error, by providing a masking material film and a photosensitive resin film successively on the glass substrate which has latticed grooves on the surface.

CONSTITUTION: Latticed grooves 1 having intervals adapted accurately to the size of chips which should be formed are formed on one face of glass substrate 2 for photomasking by the photolithographic or electron beam lithographic process. Next, masking material film 3 consisting of the conductive light shielding material (such as chromium) is caused to adhere onto substrate 2 by the vapor deposition method or the like. Next after photosensitive resin film 4 consisting of the photoresistor or electron beam resistor is provided on mask material film 3, resin film 4 covering grooves 1 of glass substrate 2 and regions approximately 1μm wide around grooves 1 is removed selectively to obtain dry plates for photomasking.