A photomask comprises: a light transmitting substrate; patterns disposed over the light transmitting substrate to define a light transmitting region; and a light transmittance control layer disposed between the light transmitting substrate and the patterns having a relatively high light transmittance in a first control layer region overlapping a first portion of the light transmitting region adjacent to a poor pattern having a size larger than a normal size than in a second control layer region overlapping a second portion of the light transmitting region between normal patterns having a normal size.