A method of fabricating a photomask comprising providing a photomask blank including a phase shifting layer, a first light blocking layer, a first resist layer, a second light blocking layer and a second resist layer stacked sequentially in this order on a substrate, forming second resist patterns, forming second light blocking patterns, forming first resist patterns, forming first light blocking patterns and phase shifting patterns, removing the first resist patterns, and selectively removing at least one of the first light blocking patterns, wherein the second resist layer has a thickness such that all of the second resist layer is removed while the first resist layer is patterned for exposing the second light blocking layer.