a pattern forming method comprising the steps of : detecting a position of a base pattern formed on a substrate ; forming a photosensitive resin film on the substrate ; correcting a pattern data of a pattern to be formed on the substrate , based on a positional information of the base pattern to thereby compute a corrected pattern data ; displaying a mask pattern on a liquid crystal panel , based on the corrected pattern data ; and exposing the photosensitive resin film with the liquid crystal panel as a mask and developing the same to thereby pattern the photosensitive resin film . even when a base pattern has rotations , shrinkages , distortions , etc ., a prescribed upper layer pattern can be formed in alignment with the lower layer pattern .